On the spectrum of reality, the concept of "Elle Fanning" has, classically, been diametrically opposed to the concepts of "cannibalism" and "necrophilia" and "literal bloodbaths." This is no longer the case. Fanning's latest film, Nicolas Winding Refn's The Neon Demon, is lousy with the sort of gory, sexually explicit horror that would utterly destroy the psyches of the characters she's played up till now — a young Sleeping Beauty, a sweet Tourette's sufferer, a friend to cartoon trolls, the angelic owner of a three-dimensional Nutcracker.

In other words, for her first "adult" role, the 18-year-old Fanning has not so much dialed it up to 11 as she has smashed the dial and lit it on fire. Refn's trash-camp hot-mess horror-comedy sees Fanning as Jesse, a small-town beauty breaking into the Los Angeles modeling world. Thanks to her porcelain skin, "deer-in-headlights" look, and a guilelessness that seems increasingly put-on, Jesse is an instant hit, meaning, of course, that she's also an instant threat. Among those simultaneously attracted and repelled by Jesse are a macabre makeup artist (Jena Malone), two literally and figuratively starved models (Abbey Lee and Bella Heathcote), a stereotypically creepy motel owner (a hilariously perfect Keanu Reeves), and an actual wild animal. As Jesse climbs the modeling ranks, things devolve rapidly into the realm of people-eating and corpse-fucking.

The Neon Demon is, in a word, ridiculous — at its Cannes premiere, it was so polarizing that it induced concurrent boos and an extended standing ovation. It's also a really fucking fun, high-octane, purposefully provocative, bombastic film that had me both cringing in disgust and laughing out loud. It's an exercise in opposites, much like Fanning herself, who, when I meet her at New York's decidedly Neon Demon–esque Nomo Soho, is clad in an all-pink ensemble — lacy pink slip dress, satin pink choker, pink cheeks — and cheerfully inviting me to sit next to her on a couch rather than across from her in my own chair. Two nights earlier, I'd watched this same young woman deep-throat a knife.

Tell me about meeting Nicolas. How did he sell you on this whole thing?

Elle Fanning: [Laughs.] I was in South Africa, and I was doing a film, and there were two channels on the TV. One was in Afrikaans, so I couldn't understand it, and the other one was a movie channel, and they only played Girl With the Dragon Tattoo and Drive. So I'd turn it on and be like, "Oh, Drive is on again!" and watch it. I kind of got introduced to Nick and his style in that way. I loved the world he created — that's such a great movie. And when I got home, I heard Nick was doing a movie about the fashion world and the teenage girl was a lead in it. Which is very shocking because he's, like, the king of masculinity and violence. So to combine that world of his into a young girl as a model? That just seemed like the coolest thing, so different, and I really wanted to be a part of it. Even before I read the script, I was like, "Yes!"

We must have had psychic powers, I guess, because he asked to meet me. So I get to his home in L.A., and there's princess clothes everywhere. He has two young girls. So I realized why he wanted to do this movie — he has all these feminine forces around him. He described the story to me, and I was just all in. I found it fascinating.

Is that when he asked you if you found yourself beautiful?

Fanning: Yes! He asked me that. It's such an uncomfortable question. The subject of beauty is very taboo, which is what our movie is about. In that moment, we kind of realized what the film was: If you say yes, you're a complete narcissist. But then also, you should say yes, because everyone should love themselves, should think that they're beautiful. There's a fine line, and crossing that line is when you get into dangerous territory.

What'd you say?

Fanning: I laughed, but then I said yes. We were just getting to know each other, and when I said that, we realized what the film was. It was like, we're ready, we're off, let's go.

So you had input on what the film was going to be?

Fanning: Yeah. It was really — I'd never worked that way before, as closely with a director. It was very intense, and I'd come to set in the morning, and he'd be like, "What do you wanna do? Where do you want to stand?" And they'd design the scene around that. It was like, "Oh!" You kind of feel this power [laughs]. We filmed in chronological order, so all in sequence, which I'd never done, and was so helpful for [playing] Jesse because of the transformation that she has. And because of things that happened the day before, we'd be like, "Oh, OK, since that happened, we can't do the scene that way anymore. We have to change it." So it's like, "All right, let's think of something else." It was very spontaneous. You're constantly going off of your instincts. Nick is a genius. He has a script, and that's the structure of it, but the movie isn't as much like the script [as most movies]. There's stuff that wasn't in there. You're discovering things along the way.

You really went all the way to the opposite end of the spectrum for your first so-called "adult" role, what with all of the sex and violence and cannibalism and necrophilia. Did that make you nervous at all, in terms of doing that sort of work or how it might tweak your image? Or was that part of the goal — to upend that image, like, "I'm 18, I'm ready to make this kind of movie?"

Fanning: You know, it really wasn't on purpose at all. I was 16 when I did it. I just loved the concept of it, having a female character who you think is the victim and is not, and is such a strong character amongst a cast of ladies, which was amazing. It just worked out that, with this movie, so many milestones have happened. I turned 17 while filming. We got into Cannes, my first time at Cannes. My prom night was on the premiere night, so we had prom night in Cannes. My best friend came out; he was gonna go with me. I turned 18, and I graduated a couple of days go. I feel like I've grown up now more that it's coming out, and I think it's the perfect timing.

The reactions to Neon Demon have been pretty polarized, especially at Cannes, where it was simultaneously booed and got a standing ovation. At my screening, some people were laughing, others were hiding behind their hands. What's been your reaction to these reactions? What do you and Nicolas want people to take away from the movie?

Fanning: We knew that that was going to be the reaction. I think it was perfect, actually. Some people love it, some people hate it, but it's not boring. It's going to stay with you and you're going to talk about it. It's unlike anything I've really seen before, in a long time at least. Having that was very exciting. It's art — you can't say art is good or bad. Everyone has a different opinion on it. And everyone should.

The movie is at least partly tongue-in-cheek and very campy. I'm interested in how Nicolas got those performances out of everyone — did he instruct you to play it that campy? Or were you told to play it straight?

Fanning: We knew that there were elements of camp. And having Keanu Reeves in the movie — and having him play bad — was so funny. Because he's the hero, usually. That was awesome. It's a classic horror film, in a way, where it's like, "The star is born and is going to be corrupted by the city." But then it takes a twist. Nick said it was like Dorothy in Oz, but if she were evil. I did watch Valley of the Dolls and Beyond the Valley of the Dolls, and this movie called Night Tide about this mermaid who's a killer [laughs]. I was kind of inspired by those elements, that type of campiness, but you're not thinking, Oh, I'm going to play this [campy]. It's also very truthful, as well. Nick is all about subtlety — everything is toned down to its rawest form. And he does a lot of takes, too, to discover new things.

I wouldn't necessarily call this movie subtle...

Fanning: [Laughs.] The characters are subtle, but everything around them is not. The opposites of it — that's what makes it so great. The little reactions to giant things.

Like that little lip curl at the end.

Fanning: Ahhhh, Abbey is SO good! She is so funny.

It's also very much fixated on the way that women in Hollywood are extremely jealous of and competitive with one another. Has this been your experience of it?

Fanning: There's competitiveness in everything. In your job, too, I'm sure. I think there's also this stereotype that women together are catty and competitive, which is just — nobody ever talks about men being catty or competitive. I don't think that's fair. Women can work in an environment and be not like, you know, [bares her teeth and hisses]. I haven't had that much experience with [cattiness]. I mean, yes, we're all trying to do the same thing, but that's both men and women. So I haven't felt that very much.

That's part of some of the critique of the film, though, that it is forwarding that tired notion of women being catty. What do you think of that reading of it?

Fanning: I think that it more has to do with the essence of beauty. Beauty is a very uncomfortable topic to talk about, obviously. There is a truthfulness to that [stereotype], but it doesn't just have to do with women. It has to do with the world. Especially with the social-media generation. Nick is looking at narcissism as a virtue, which is also very uncomfortable. We're taking selfies every minute. But is that a bad thing? My generation, we're more accepting of narcissism. But we're looking at these images that are dead, that are on your phone. My friends have apps to make you look skinny, to make your skin look perfect. And we look at these images and we're like, "That's beauty. That's perfect." But when you see a real person, you're like, "Wait, that's not perfect." So you're driving yourself crazy trying to achieve this dead perfection you're looking at on your phone. And that's scary.

You're not really on social media, are you?

Fanning: I just got on public Instagram.

Why now?

Fanning: I turned 18, it was on my birthday. I just decided, "I'm gonna do it." I had a private Instagram, and my sister [Dakota] did it a month or so before me, and I was like, "OK, if she did it…" Because she's a very private person. My whole family is very private. I've always been scared of the social-media thing.

What scared you about it?

Fanning: I think just being so out there in the world, letting people know what you're doing all the time. I don't have a Facebook, I never have. I don't have Twitter, I never have. I think my parents are very protective, too, so they didn't want us to have any more exposure. But Instagram is a photo that you control. And you can talk to your fans, or talk about the movies you do — slices of your life. It's like a Tumblr, a little bit. It is what you make it.

Your parents are protective — what was their reaction to the things you had to do in this movie?

Fanning: My mom was on set every day. She read the script. And of course there were legal things, people had to approve [of my scenes]. But also, I didn't do anything too crazy.

You definitely got the best deal in that sense.

Fanning: I did! I was fine. And she saw the movie in Cannes and got very emotional.

Why do you think she was emotional?

Fanning: Our screening got a big reaction. Everyone was clapping. It was such a huge group of people. Even me, I was very overwhelmed. I think seeing her daughter onscreen, all big like that [laughs]. And maybe it was because of me growing up.