Funny debates.
I think both glamour and porn have their respective markets in modern society. To say that porn is somehow lower than glamour, is a bit prejudiced. It takes just as much skill and artistic ability to make a good porno clip which shows enjoyment and celebration of sex, as to make a nice glamour shot. But my (limited) experience with porn, usually the distance of the actors and their passivity shows through. Then it becomes disgusting.
But then I'm a man and enjoy feminine shapes...
First shot:
Don't let direct light fall on the wrinkled cloth. This will reduce the effect of wrinkles.
Face is overexposed
You should position her parallel to the plane of focus. The lens is wide enough to make her calf look too big.
No on camera flash! (for all shots)
Second: Lack of purpose. I see bones, not curves. I don't see the face. Doesn't work, she's just sitting there...
Third: Is kinda interesting, but she looks more scared/apprehensive when staring in the camera. And her superior and inferior do not match.
The hands are spaced for a jump, as well as the face. They communicate aggression and attack mode. If you wanted that, she should've been sitting on her toes, ready to jump.
But the inferior communicates mating call and passivity. If you wanted that, make the model cross her hands, lay her head on her hands and looking into the camera. That would give the mating call.