'The September Issue': Vogue's Anna Wintour is the big chiller

n "The September Issue," director R.J. Cutler aims to address one of the burning questions of our time: Is Vogue editor Anna Wintour really the Devil in Prada-designed disguise?

To his credit, Cutler evades an easy answer. Hate her? You'll find plenty to fault in this portrait, which was shot in 2007 as ­Wintour and her staff planned the magazine's all-important fall fashion ­issue. Love her? Expect to walk out wondering why the personalities of male executives are so rarely dissected in such an unsparing way.

Really, the more curious question is this: Why would Wintour have ­allowed Cutler's cameras into her office in the first place?

Though unapologetic about her management style—to understate, she does not suffer fools gladly—she would seem to have little to gain by exposing herself to the masses.

Like any unusually successful ­businessperson, she is perfectionistic and demanding to an extreme degree. But that alone can't fill a movie; there are only so many times we can watch employees cower in her imperious presence.

Fortunately, Cutler found an ideal contrast in gifted stylist Grace Coddington. Funny, frowsy and ­unashamedly outspoken, Coddington is outraged by Wintour's coolly practical mentality. Freed from the burden of a bottom line, she's able to focus entirely on the art of fashion, as we see in the exquisite photo spreads she arranges—and, often as not, Wintour dismisses.

Their tense push-pull ­between creativity and commerce is the most interesting aspect of the film, though Vogue readers will love the—other behind-the-scenes details, ­including a ­hilarious takedown of cover girl Sienna Miller.

But when it's all over, we still don't know who Wintour really is. Do the bangs and sunglasses serve to hide any worries or insecurities? Does she care about her public persona? Is she happy, or just driven?

We get a few warm moments with her daughter, when she softens into a typically proud parent. But for the most part, she keeps Cutler—and us—at a frosty distance. Maybe there honestly isn't anything else there. Or maybe she used those cameras to perpetuate an image that has served her so well she sees no reason to reveal anything more.