Possibly the most glamorous tourists ever to hit London—Karl Lagerfeld and the Chanel posse—arrived in town this week in a flurry of flashbulbs to present the house's Métiers d'Art pre-fall collection over a two-day razzle-dazzle round of cocktails, dinners, and partying. Why? It's the right time and the right place to bring out a super-special collection, sandwiched in a sweet new spot of luxury between ready-to-wear and haute couture.