Like the world of high fashion the magazine focuses on, there’s plenty of glitz but precious little substance to R.J. Cutler’s documentary about assembling Vogue’s September 2007 issue—the publication’s most eagerly-awaited and influential number of the year. It follows editor-in-chief Anna Wintour as she coolly visits designers like Oscar de la Renta, Jean Paul Gaultier and Patrick Demarchelier, who treat her like royalty, as well as fashion shows, to choose items for inclusion, while icily dismissing most of those on the endless racks of clothing in the Vogue offices and most of the photographs taken by one of the many teams overseen by her subordinates.

The British-born Wintour emerges as the undoubted star of the show. She comes across as a fairly dour, unsmiling presence, loosening up appreciably only in scenes at home with her daughter, who insists—to mom’s displeasure—that she has no desire to follow in her footsteps. Her demeanor is explained somewhat as she talks about her own biography; when she speaks of her father, a serious political journalist, and her siblings, who hold similarly lofty positions and are “amused,” as she puts it, by what she does, you can glimpse her sad irritation at being treated somewhat condescendingly by family members who look upon fashion as something rather frivolous. The same sense of defensiveness comes when Wintour suggests that those who dismiss haut couture as insignificant are really motivated by fear and a failure to understand what it’s all about. (Of course, those who see the entire world on which Wintour lavishes her talent as a flighty, ephemeral exaltation of mindless excess might just be right.)

But Wintour isn’t the only person in the cast who makes an impression. She’s very nearly equaled by Grace Coddington, her creative director, who’s frequently at odds with Wintour’s decisions and willing to express her discontent. We get a nice biographical sketch of her, too—a former model who turned to the publishing side of the business after she was injured in an auto accident. Like her boss, she seems none too happy, though the two women clearly respect one another even when they disagree. (Curiously, neither dresses very elegantly—especially Coddington, whose sack-like dresses actually look a bit frumpy.)

Most of the other people who circulate around Wintour and Coddington seem rather anonymous, with a few exceptions. One is Thakoon Panichgul, a young designer whom Wintour has taken under her wing and whose designs she’s promoting as part of a project to encourage American fashion. Another is Mario Testino, the chatty, self-absorbed photographer chosen to shoot the layout with the issue’s guest celebrity model (a Wintour invention), actress Sienna Miller, in Rome (and who disappoints his employer by failing to provide a Coliseum shot she wanted). (Miller, by contrast, comes across as rather vacuous.)

And then there’s Andre Leon Talley, the magazine’s flamboyant editor-at-large, a big man with lots of outrageous opinions. He’s basically used as comic relief; we’re never really shown what he does, but Cutler and editor Azin Samari periodically insert sequences showing him saying things like “We’re suffering from a famine of beauty” and half-(or maybe quarter-)heartedly banging around balls on a tennis court because Wintour told him he’s too chubby.

The Talley material represents what’s wrong with “The September Issue.” It’s just empty filler, like so many of the montages of dresses and fashion runways that Samari tosses together. We’re shown Wintour making the rounds of the office, choosing this photo and excising that one, or dismissing dresses because they’re black (she wants more color), but there’s no serious attempt to penetrate her brusque exterior (following up on her recollections of her family, for instance), or to give a coherent picture of her overall aesthetic. Instead we’re left with a few observations that fashion is more than overexpensive frivolity, which is just what we’d expect her to say. In the end we’re as much in the dark as Coddington about why Wintour makes the decisions she does. Of course, it’s the bottom line that matters, so it’s understandable that her publisher should gush over her so, or that the chief of Nieman Marcus should do everything he can to compliment her—as both are shown doing here.

The film basically follows their lead, and as a result plays more like an authorized puff-piece rather than a serious attempt at documentary analysis. Vogue readers and fashionistas everywhere may enjoy the movie, but others may well take issue with such an oddly toothless portrait of a bruising business. Somehow one suspects that “The Devil Wears Prada” wasn’t just more fun, but maybe more accurate too.