You got lots of great comments on this, and I think you placed wonderfully in the challenge.
Composition
I liked the simple composition of this image. It focuses the viewer on your subject and message. I felt, however, that the camera was too close to the subject and I would have wanted to view this scene from a little further back. I would not have complicated the background or any with this, but might have chosen a lighter bg, or better light bg if there was too much black in the image from moving further away.
Colour and lighting
I think the lighting on your subject is well done, but i find myself looking for a little more light on the subject, especially near the right arm/right side would have been useful to even it out a bit. It is a bit dark and seems to trail off on that side. This also seems to affect the focus there which isn't as clear as the rest of the photo.
OVERALL, I think this was a very well done image. It would also work quite well in black and white as the colour isn't particularly vibrant or essential to the message of your image.
Hahahahaha....nice concept...lack of contast on her hair vs the background is problematic.....perhaps a shot from to POV of her looking in the mirror....hey you get a 7 for originality....