The women's poses are engineered to show off their secondary sexual characteristics. They thrust out their breasts and asses, and the movement in the pose focuses on sensual curves instead of strong, solid power. And did you notice the focus on drawing female superheroes as sexy instead of, say, strong or fierce in the How To Draw pages? They stand in ways that are off-balance - in many pages STANDING ON TIPTOE - and that would cause them to be knocked flat on their asses if you gave them a push, unlike the male superheroes who are drawn in poses with solid stances.

Note that the male superheroes do not have to be attractive, but that an en tire chapter is devoted to making the women sexy. Not to mention that in the general "Here are the correct proportions for a woman, she is shows standing on tiptoe like she's wearing heels (http://pics.livejournal.com/ratcreature/pic/0008fd6h), with her breasts and putt protruding, and her hands in a horrible, horrible position. (There is NO REASON to hold your hands like that - and as that's a horrible way to make a fist and it makes your hands weak an vulnerable, it serious detracts from any impression of strength she might have otherwise. It's a girly pose, rather than a feminine pose.)

Note that the men standing in those positions in vito_excalibur's version all look weak and off-balance. That's because they are.

And yes: breasts are secondary sexual characteristics that are over-emphasized out of all proportion in a sexual manner in these drawings. That curved-back-protruding-chest pose is a pinup pose, and anyone posing like that is deliberately emphasizing their sexiness, not their strength.