The Wintour of almost content

The ice queen of American fashion, Vogue editor Anna Wintour, keeps her cool in The September Issue, RJ Cutler's absorbing documentary about the creation of the September 2007 edition of Vogue, which at 840 pages became the single largest issue of a magazine ever published.

It's a carefully controlled performance, designed perhaps to counteract Meryl Streep's villainous Miranda Priestly, the fictionalised version of Wintour from the movie adaptation of the book, The Devil Wears Prada.

Still, there are moments here when the temperature drops low enough to give you a chill. "Is this all we've got?" a clearly displeased Wintour asks of an assistant while looking through a photo shoot by well-known photographer Mario Testino.

Elsewhere, she plainly tells Oscar De La Renta that one of his designs isn't good enough for his runway show.

But the impression is that Nuclear Wintour was on her best behaviour while the cameras were rolling for the four months leading up to the print date, and that, judging from the way Vogue's skittish staff tiptoe around their fearsome editor, there's more to this story than met RJ Cutler's eye.

Instead of tyrannical tantrums we get Wintour's softer, more vulnerable side. Wintour even betrays some insecurities about her English family's dim view of the fashion world. But we also get a taste of her business acumen in a meeting with advertisers, and of her fashion world clout - Wintour, famous for nurturing new talent, secures a highly sought-after Gap contract for young designer Thakoon. At one point Andre Leon Talley, Vogue's eccentric and hyperbolic editor-at-large calls Wintour the most powerful woman in America." It's such a flattering portrait that it's no surprise Wintour has publicly approved of the film.

Ultimately, though, this film isn't about Wintour or even the allure of fashion, it's about all the hard work that goes into the making of the magazine, one that, in pre-recession 2007, was read by one in 10 American women. So we see leggy interns hurriedly wheeling racks of designer clothes down the corridors of Vogue's Times Square HQ, the world's biggest walk-in closet, and we follow Wintour and her entourage to the catwalks in Paris and Milan, where she sits behind her Jackie O shades in the front row, arms folded, lips tightly pursed.

But because it's the work Cutler is interested in, it's Vogue's tireless fashion editor, Grace Coddington, a fiery-haired ex-model, who emerges as the film's other star.

Coddington is the lone voice of dissent to be heard in editorial meetings, and she is unafraid to criticise her editor on camera. She is also visibly upset when she receives word that Wintour has canned a 1920s themed photo spread worth $50000.

But if their relationship is fraught it is also immensely productive. Coddington may be a "creative genius" who sees fashion as art, but she needs Wintour, who thinks also of fashion as a business, to rein her in and keep her in check.

When the impressive September issue is signed off, it's clear that their combustible partnership is the key to Vogue's success. It's an interesting symbiosis, one regarded by many as the most powerful relationship in fashion.