I thought it a little weird when I noticed it myself. The only magazine I knew of which was the opposite was Australian Womens Forum, and that went out of business.

I suspect that it's all part of the marketing to insecure women and using the covers to make women walking past them more insecure and therefore more likely to buy the magazine.

On the other hand, men's magazines have recently started similar tactics. Perhaps sexual insecurity is universal, particularly amongst the younger demographic such publications tend to target.