http://mashable.com/2009/09/01/women-wikipedia/
http://www.nytimes.com/roomfordebate/2011/02/02/where-are-th...
Incidentally; Wikifashion is genius. I'm totally going to score points by showing it to my fashion-obsessed-and-wikipedia-contributing girlfriend tonight.
http://www.top-fashion-designers.info/
So it seems reasonable to assume that her site could pull in more than a few guys, making the mere 7% a bit surprising. I have no explanation to offer for that though, not even a guess.
It's not about appreciating beauty, it is about having good taste.
Also, to contrast with wikipedia, certain kinds of anti-social behaviour, arguing and power-seeking are not just encouraged, but practically enshrined at wikipedia. Frankly the only surprise is that it isn't even more of a sausage-fest.
While Wikifashion is pretty and, that beauty certainly (I'm sure) helps contribute to it's success: Don't you think your high female contributor ratio has more to do with your subject matter being more interesting to women?