Can I have both of them?
Now..seriously I prefer the pose on the second one ITS A CLASSIC! Hot girl with glasses in that position makes me think of any boy`s dream about the hot teacher LOL! Reminds me of David Lee Roth or Aerosmith old videos with hot nurses and naughty teachers PMSL.
Love the soft shadow on her right eye, the sexy mouth and naughty eyebrow....Its hard to think of any photographic terms at this point....sorry

On the first pic its lacks all those details I particularly like, plus the hair is much better on the second also.