Of all the ways to mix up the tried-and-true show format, an unannounced haute couture collection is certainly an interesting tactic. Especially in the context of the industry's current conversation about shifting toward a consumer-facing calendar. Made-to-measure design is pretty much the opposite of the speedy "see now, buy now" switch that took over runways (and how we talked about shows) in New York , after all. Hedi Slimane didn't need much to get people talking about part two of his fall '16 collection in Paris. (The first half premiered at the Palladium in Los Angeles on February 10.) But the resulting discourse went in a few different directions.Firstly, Slimane made it clear Saint Laurent was going back to its roots with a surprise couture presentation, titled "La Collection de Paris." There was no soundtrack to accompany the show. Instead, each of the 42 looks was announced and assigned a number, as was customary at the YSL couture shows from 1977 to 2002. (Bénédicte de Ginestous reprised the role of announcer, which she held for the fashion house's 25 years of showing couture.)In a more modern twist, those not lucky enough to score an engraved seat for today's show could follow along on Twitter: The brand's official account was offering live commentary (in all caps), sharing images of the numbered looks as well as additional details on the collection as the presentation unfolded in Paris. While some (like WSJ's Christina Binkley ) had correctly predicted that there would be couture, not the usual RTW fare, at this season's showing, it seemed like a surprise to most.