I have no idea why I am doing this to myself...

...i.e. reading Frank Cho's chapter on how to draw effective covers from Wizard's "How To Draw: Advanced Techniques". To quote one of the many great pearls of wisdom (emphasis not mine, btw):

"VIVE LA DIFFERENCE!
You also can't use the same pose for guys and women--and women are much harder to draw covers for. With guys you just have to convey power to make the figure work, while with women, you have to emphasize their, y'know, curvaceous nature. It's almost like a swimsuit-issue pose--you have to emphasize their curves, yet at the same time reflect their power as well.
[...]
SKETCH APPEAL
Drawing a cover is mostly just trying to come up with a strong pose and trying to build upon it. It's kinda hard when you're drawing girls, because you're trying to come up with a strong, dominant pose, yet at the same time make it very sensual and sexy. I was just playing around with various poses, and for whatever reason none of 'em were sexy enough for me."

I don't have the pages scanned right now, but looking at the sketches illustrating that last bit I'm really wondering why anyone would consider sitting with spread legs and a "flirty" look towards the reader to be a "strong, dominant pose" for women. BTW, the solution for why the first ones weren't "sexy enough" becomes apparent when you look at the sketches, since the first ones are not showing the woman sitting with her legs spread. You'd think the cover example for "dominant + sexy" would show something like that Wonder Woman cover where her boot grinds down on Batman's head, but apparently not....