Thom Browne’s shows are pick performance art over practicality, in a way that makes them very rich to behold. This one, his inaugural in Paris, jumped off from “[t]wo girls dreaming of unicorns and mermaids, and all the things that little girls dream of,” sampled “Part of Your World” for the soundtrack, and included details that evoke aspects of life under the sea — all while telling the story of two twins who fall asleep and wake in a world where “everyone is beautiful.” I have never been to a Thom Browne show, and BOY am I sad about that. This looks like it was a buoyant, wacky sensory feast. And yes, there really is a unicorn.