The subject seems to have that deep sense of longing. Either for a loved one or one that should long for her. Regardless, the entirety of the picture seems to say so much more than it initially lets on.
It's captivating, beautiful, and heartbreaking. I would draw this and never be able to capture those feelings.
I agree that b&w was the only choice for a picture like this. The lighting could not be better and I like the way the hair frames her face. Black top and dark nail polish finalises the setup.
The title of the picture provides a certain angle to look at this picture and now that I do, I get also a sense of vulnerability. In addition, a bit of sadness and perhaps even a touch of insecurity and distrust towards the viewer with her hands kept close to her chest as if reluctant to open herself.
All in all, an excellent picture, me like!