Chest bindings were also a hit with the men, at one point. Not only that, but those pecks are too well-defined (and sex-ay) to belong to a woman as frail-looking as Zelda. Actually, everything about Sheik's body is too big and toned to be Zelda's female form. And then there's the obvious lack of hips. Sheik may not be male, but one thing that should be established just by looking at the two character models is that Zelda's body does go through a metamorphosis when turning into Sheik. And, considering that, and the fact that Sheik is referred to as being male in the actual game, it isn't entirely unthinkable that when Zelda's body changes when she magically transforms into Sheik, she takes on the male form to further throw Ganondorf off her trail and traverse Hyrule undetected.