The first 15 minutes of “The September Issue” trip along self-promotingly, an ode composed in Her glory. Who, her? Anna Wintour, you simpleton — editor-in-chief of Vogue. In a meeting with Wintour, elusive Chanel designer Karl Lagerfeld presents a tweed suit, muttering in his befuddling Euro accent, “This one we call Anna.” Um, scusi? If fashion were the Old Testament, Karl would be Moses. What the hell does that make Anna?

This ass-kissing documentary tracks the creation of the 2007 September issue of Vogue, the biggest issue in the magazine’s history. As the editors set to work planning the month’s fashion spreads, we meet the true star of film, Grace Coddington. The creative director’s struggle to make beautiful photographs — and keep them from being cut out of the issue — quickly becomes the focus of the doc. Our villain: the eternally business-minded Wintour. It’s like “Alien vs. Predator,” but with supersized Starbucks drinks and Louis Vuitton tennis towels.

While Wintour and Coddington frequently allude to their ability to work together, it is really this contention between the two personalities that makes the film so enjoyable. Anna is airbrushed and icy, with her baby-bird figure and flawless blonde bob: Grace has wrinkles and this wonderfully nasal Welsh accent. Anna axes Grace’s favorite images from the ’20s-inspired photo shoot: Grace wanders around like this harmless witch in baggy, black Prada. When Anna isn’t about, Grace complains about half of her pictures getting “killed.” Her words, not mine.

In one ridiculously clear moment of distinction between the two women, Anna declares that they should retouch the cameraman’s portly stomach — Grace had recruited the filmmaking team to take part in a photo shoot. From out of the frame: “She told me I needed to go to the gym.” Grace champions the poor guy, declaring, “Everybody isn’t perfect in this world … Please do not retouch Bob’s stomach.”

If you’re in the mood for some fashion-porn, there are plenty of delicious backstage moments. The live footage of the shoots is choice. (Read: watching Caroline Trentini jump in front of a gray backdrop, and Raquel Zimmerman, in full makeup and wig, daintily biting into a pastry Grace bought her.) Peripheral figures also float in and out as the issue comes together. The editors make disparaging remarks about covergirl Sienna Miller’s teeth (“There are a couple fillings there”), hair (“Her hair is not looking its best”) and teeth (“What about her teeth?”). In one aside, Editor-at-Large/Berobed caricature Andre Leon Talley has a tennis lesson, which basically means swatting hopelessly at tennis balls with a Louis Vuitton towel draped around his neck before taking a water break. He keeps his water in LV-stamped cases, obviously.

“The September Issue” is pretty much a promotional documentary. In exchange for a few bj’s, we get to see some brilliant footage of fashion events. Plus, there’s this awesome scene in which Anna literally eviscerates an assistant who screws up her coffee order. Don’t believe me? Go see it for yourself.