For more than 30 years, Jean Paul Gaultier has waved the “enfant terrible” flag in French fashion. He is one of those designers whose vivid public persona might approach self-caricature—but also is a formidable marketing force, an invaluable part of the brand. So what is shorthand forGaultier? Breton stripe, peroxided hair, brilliant tailoring—and a cheeky, cheerful irreverence.