Yep, Lorde made the most of being burdened with a cast by having her fellow Met Gala attendees sign it. There's Taylor (Swift, maybe you've heard of her?), Lily (Collins, her date for the evening), oh, and someone who goes by Yeezus.
Sure, it would be unreasonable for Lorde to ask to keep her cast on longer than necessary, but, LBR, you'd totally get why if she did, right? Cool, same.