It takes something special for Anna Wintour to miss a fashion show.

With her signature bob, oversized sunglasses and a perpetual look of annoyance, the longtime editor of Vogue magazine is a front-row fixture at New York's Mercedes-Benz Fashion Week, where America’s top designers have been showing their spring 2010 collections this week.

But she was MIA at the Diane von Furstenberg show last Sunday when her other passion – tennis – took center stage. She ditched Diane to watch her favorite athlete, Roger Federer, compete in the U.S. Open.

Wintour is so crazy about the sport that in the new movie, “The September Issue,” opening in Houston Friday, she says the only thing she wishes she had was “a better backhand.”

Covering fashion shows in New York and Europe for much of the past decade, I have rarely seen her giddy. She is punctual, arriving at every show at the appointed time – usually a half hour or more before it begins – but she rarely looks amused. I don’t think she would be much fun at a dinner party. Heck, I wouldn’t even want to share an elevator with her.

But when she sat next to Federer at the Oscar de la Renta show two years ago, the day after he won the U.S. Open, the then-57-year-old Wintour acted like a smitten schoolgirl.

And her ice queen image melted just a little bit.

In recent weeks, her reputation has continued to thaw, thanks to the new documentary that details how she and her staff put together the September 2007 issue of Vogue – the largest in its history at 727 ad pages.

In the movie, Wintour comes across as harsh and exacting – just as the fictional character reportedly modeled after her in “The Devil Wears Prada.” But she also shows surprising vulnerability.

Despite her queen bee position in the fashion world, she seems sheepish in the movie about her accomplishments compared to her siblings, who work in political journalism, labor relations and low-income housing.

“My brothers and sister are very amused by what I do,” she says in a tone that approaches embarrassment.

I saw that more human side of her last fall, after I arrived very early at the Fendi fashion show in Milan and was seated directly behind Wintour. With only a few people in the room, I figured it was a good chance to corner her.

Over the years, I had occasionally approached her to ask a fashion question, which she politely answered before dismissing me with a “You can go now” look. However, this time, she was much warmer.

When I said I was from Houston, she wanted to know how people were coping since Hurricane Ike had hit a week earlier. Her longtime significant other, Shelby Bryan, is a native Houstonian and she said she regularly visits the city with him.

“I love Houston. Everyone’s so friendly,” she said. “We have an apartment in River Oaks and I hear that (area of town) was badly hit. A lot of people I know left. I hope it gets back together again soon.”

On Monday, at the Carolina Herrera fashion show, I snagged a few more minutes of her time as she waved off her security guard to let me get closer.

Despite the less-than-flattering portrayal, she is a big fan of the movie.

“I thought it was a very insightful documentary about the inner workings of a magazine. So many people don’t understand the incredible hard work and talent and creativity that go into the making of any issue, but particularly the September issue,” she said. “I hope people in Houston enjoy it.”

She admitted that she thinks about some of footage that had been left out and one gets the impression that, as an editor, she would have crafted it differently.

“But this is very much R.J.’s vision,” she said, referring to director R. J. Cutler, “and so far the reviews have been very positive. The movie’s doing well and I’m obviously happy for him because he spent two years of his life on it. So I’m glad it seems to be working.”

While Wintour is such a force at the fashion shows, in the movie she is overshadowed by the magazine’s creative director, Grace Coddington, a flame-haired dynamo responsible for many of Vogue’s most memorable photo spreads. If Wintour is the brains of the operation, Coddington is its heart.

The two women started at Vogue on the same day more than 20 years ago. Their relationship is fractious but respectful. It’s hard to imagine one working there without the other. It’s also surprising to realize that a magazine that airbrushes out most imperfections is run by two women who appear happy with their wrinkles. Neither, Wintour, who turns 60 in November, nor Coddington , 68, appear to have had cosmetic surgery.

Vogue has shrunk substantially since the movie was filmed. The September 2009 issue had only 427 ad pages. The consulting firm of McKinsey & Co. was recently hired to scrutinize the magazine and find ways to cut costs. The fashion crowd is speculating how deep Wintour’s cushy clothing allowance may be cut.

But the most powerful woman in fashion has come up with a response to the economic slump: Go shopping. She spearheaded “Fashion’s Night Out” on the first night of fashion week in which a lot of tony New York stores sponsored special events to get shoppers to open their pockets and pocketbooks.

As for her absence at the Von Furstenberg show, she explained that she previewed the collection a couple of days earlier.

“Diane is a very good friend of mine and she understands that I was at the tennis (match) for my other good friend, Roger Federer,” Wintour said. “It’s not necessarily about always being in the front row of a fashion show."