When you look in the mirror, on Instagram, or in the pages of New York, you’re just looking at Charli XCX and her sprawling international consortium of hotties. Her album brat is partly dedicated to the muses featured in her music video for “360” — Julia Fox, Gabbriette, and Rachel Sennott to name a few — and to the producers making the songs bump, like her friends A.G. Cook, EASYFUN, and The Dare. But invites didn’t just go out to Charli’s (brat) green-room besties...