Couturissime is a superlative that means “beyond couture,” and that’s where this exhibition, the first ever on the couturier Thierry Mugler, takes us. Organized as an opera in seven acts, Mugler’s designs—inspired by animals and insects, the Belle Époque and Belle de Jour, human folly and future fembots—are like arias with an hourglass shape. —L.J.