Male poses in video games and movies are very différents, walking up front can be used as a way to express resolve, courage, tensed muscles as a way to show anger, strenght, decontracted poses to show badassness etc…

But the typpicals female poses are completely devoid of any behavior, “they just look nice” or sexy. Regardless of the context, and are just here as a way to say “Hey look, isn’t she pretty? See? See how pretty she is? Isn’t that cool?”

It’s not an universal law and you’re free to show some counter examples, but the large majority of female représentations in advertising and entertaining still match the description.

What makes the figure on the right female?

If anything, the images clearly communicate something about aggression.  Forward-facing and active poses are widely perceived as aggressive across circumstances, societies and even species; and the characters on display here are generally positive (or at least important) characters.  Combining positively-coded characters with gendered portrayals of [non-]aggression seems to pretty clearly reinforce the idea that good men are aggressive and good women are not – which, conveniently, dovetails well with the way most (Western at least) value aggression in men and condemn it in women, or at least tend in that direction.

I don’t see why we should take the suggestion that pose communicates something about other behavioral traits, though, like mischeviousness or uncertainty, without significant demonstration of such associations in the culture in question.  If anything, those traits seem to me to be associated more strongly with given facial expressions than with poses, which in particular makes the image of two athletes, where no face is visible, difficult to associate with such things.

Cracked.com has these really funny articles on actors who look the same in every movie poster.  Really worth a look, if only for laughs.

http://www.cracked.com/article_20288_8-actors-who-look-same-every-movie-poster-part-3.html

http://www.cracked.com/article_19903_9-actors-who-do-exact-same-thing-every-movie-poster_p2.html

http://www.cracked.com/article_19093_8-actors-who-look-exactly-same-every-movie-poster_p2.html

You’ll find that movie posters in general are not good tools for this gendered pose analysis, at least when it comes to head shots.  Body poses are definitely more gendered.  But look, it’s really common now for movie posters to feature all the actors, which poster artists heavily complain about, because it diminishes the artform of posters (and YES, it’s an artform)  You’ll find all sorts of variances in how actors – men, women, young, old, sex symbols, character actors etc. – face or don’t face the camera.  The hypothesis about gender stereotypes here simply does not fit.

But movie posters aside, I can’t deny that gendered poses are very frequent in magazines and textbooks and all sorts of things in our very visual modern society.  It’s worth exporing why it happens, but like Tom, I find the analysis here far-fetched. 

women’s bodies are shown to welcome the gaze either by their faces inviting your look (like Uhura) or by their bodies being displayed as having no purpose (ie. no activity) but to be admired.

As a freelance graphic designer I see this sort of thing all the time. When you say that it adds up over time by essentially being subliminally forecast to us at all times, you are totally correct. 

Almost every single stock photo I come across focuses on the male head on focusing on the shoulders, or leading a group, or looking down on a team of people. While the women photos tend to focus on posing, their hips, or sexy glances. 

I work with mostly non-profits that benefit inner city communities, and trust me it is very difficult to find stock photos representing the community that aren’t totally ridiculous. 

Just this week I looked at: 

Angry black women
Diminutive Latino men
Asians with glasses

All I needed was a happy minority family! Not only is this BS wrong, but it literally costs me money in the time it takes just to find photos that don’t fall into these stereotypes.