I see a lot of thought in this piece I can tell you spent a large amount of time working on the color. Speaking of which I love the color play.
The face of the women has both hints of sadness (in the eyes) and happiness (the mouth). I have to wonder what has happened to make her feel conflicted like this. I think it might have something to do with her heart in the box. She's holding it there like she doesn't want to be set free.
I'd like to see a little more detail in the background. I know it is not important to this picture but I think it does deserver a little more attention then you gave it.
Over all good job and I can't wait to see more of your work.