Just last week, Marc Jacobs president and recent Twitter convert Robert Duffy tweeted a request for set ideas for the label's Fall show. That apparently spurred Jacobs himself into action, and he more than rose to the challenge: As the show began, spotlights picked out the designer and Duffy tearing the brown construction paper from a wood frame structure at the back of the Armory. The paper duly removed, all 56 models were revealed, standing in formation on the raised platform and staring back at the audience.

With "Somewhere Over the Rainbow" ringing out from Frederic Sanchez's soundtrack, the first girl took to the runway in a gray sweatshirt with a crisscrossed back; full, tweedy gray culottes; ankle socks; and pointy-toe, low-heel croc pumps—for Jacobs watchers, all items more likely to provoke a somehow affecting sense of déjà vu than the shock of the new. From there, the designer riffed on many different elements of his nearly two-decade repertoire, playing with proportions, changing the buttons, but never deviating from a sweetly romantic palette of soft neutrals and pale pastels.

There were, in no particular order, trompe l'oeil bows, sequin-front/knit-back sweaters, sheer lingerie layers, sumptuous Mongolian lamb-collared shearlings, clear plastic trenches, panne velvet dresses, a Prince of Wales check three-piece suit, echoes of his Japanese idols, and vaguely seventies-ish knit dresses. Adding to the familiarity, insiders could even recognize Camille Bidault-Waddington and Susanne Deeken, "real girls" who work on the Marc by Marc Jacobs collection, amid the parade of largely unknown models.

As dreamy and serene as any Jacobs show in recent memory—and how typical of him to intuit that the world is craving serenity right now—the show played like a nostalgia trip, one so lovely it was quite easy to be seduced. "It's refreshing to see something that isn't trying so hard to be new," Jacobs, subversive as ever, said after the show. "There's so much striving for newness now that newness feels less new."

Cynics might argue that he took the easy way out this season. Let them; Jacobs would probably argue right back. These clothes are money in the bank not because they're "safe," but on account of their built-in resonances for the house's many followers, Twitter and otherwise, around the world. For all our technological advances, it's the emotional connection that makes the sale these days.