This selfie of Katy Perry and Adele raises a lot of questions.

Where and why did they take this photo? Which filter did they use? How can so much facial flawlessness fit into one frame? If our American pop princesses and U.K. soul queens can get along, why can't our actual world leaders? Can you ever just be 'whelmed?

While we'll probably never know the answers to the larger questions at play, I can at least tackle the first one.

It turns out that she of the never-ending album sales hit up Katy's second Prismatic World Tour stop in London on May 28. At some point, the two huddled up for a quick selfie, which the "Birthday" singer then Instagrammed, captioning: "...And on the 2nd LDN showthe Queen graced me with her presence."

The "Skyfall" crooner later returned the love, tweeting that: "Katy Perry was supreme tonight!"

Do you think Katy and Adele (Kadele? Adelty? BRB, workshopping this ship name...) might have talked musical collaborations during their backstage hangout? The latter artist does have a rumored new album in the works.

No biggie if not -- it's not like I'll set fire to the rain or anything.