“The September Issue,” a documentary about the production of the annual behemoth issue of American Vogue, isn’t about fashion. It isn’t about couture. It isn’t even about the fawning interns and hidden closets of high-end prêt-à-porter and coveted Chanel boots made famous by the 2006 film “The Devil Wears Prada.” Instead, this entertainingly pithy film centers on the careful cultivation of the most powerful brand in world-wide fashion at the hands of Vogue’s editor-in-chief, Anna Wintour.

Known for her oversized black sunglasses and pursed lips, the 88-minute documentary opens with an alarmingly disarming close-up of Wintour. Without her sunglasses and a twinkle in her eye, she explains “there is something about fashion that can make people very nervous.” In fact, it is Wintour herself that makes people nervous, as evidenced by the alert eyes and panicked hallway whispers of Vogue employees. She even manages to unnerve Stefano Pilati, the creative director of Yves Saint Laurent, as she critiques his fall 2007 looks. “There’s not enough color in that collection. I don’t see any real evening on that rack.” Although icy and intimidating, Anna Wintour isn’t mean; her exacting tyranny is merely a means to an end of maintaining Vogue’s iconic legacy.

R.J. Cutler, the documentary’s director, illustrates this by providing a take so flattering of Wintour, he might as well work for her. Cutler’s fly-on-the-wall approach allows Wintour to maintain her mystique while entertaining audiences by commanding designer, employee and celebrity alike to fulfill her every whim. However, Cutler’s “Wintour de force” is perfectly foiled by Vogue’s creative director, Grace Coddington, who is as fiery as her hair.

The ever-present clash between Wintour and Coddington resembles the age-old battle between business and art: Wintour, the dictatorial protagonist of Vogue’s economic enterprise, and Coddington, the Pre-Raphaelite ghost of ancient romantic values. Throughout the film, the two women continually grapple with ways to safely indulge Vogue’s readers with the unattainable luxuries of its pages. This happens through Coddington’s sumptuous couture spreads or Wintour’s decision to bring it-girl celebrities, like Sienna Miller, to Vogue’s front cover. Though Cutler’s documentary evades fashion’s other controversies, starving models, the fur industry, sweatshop-produced faux-couture, small conflicts and tiffs like the ones between Wintour and Coddington make the film accessible to audiences.

Although the movie neglects subjects that lurk below surface, the refreshing humor of Wintour’s hauteur and the film’s quippy nature keep audiences faithful to every frown, twitch and half-smile of the most powerful woman in the fashion industry.