oh, i see what you mean. sorry I misunderstood what you were asking.

the leg on the left just has her dress stuck to it because she is wet. the color of that part of her dress is very similar to her skin color, so it almost looks like two legs, but it is in fact just her dress.

take a look at this picture:
http://users.frailart.net/gakun/teenagearticle3.jpg

See how it looks like Ayu's right leg has a line on it? That's her dress. Her dress is really light pink right there and is really close to her skin color, so it looks weird. You can also see how Ayu is wet in that pic and how the dress is sticking to her. Hope this helps!