very cool effect! the expression on your model's face is perfect. I'm giving this an 8 because it does several things well - it's conceptually very strong, well titled, clearly linked to the challenge, and technically well executed. The only reason I'm not scoring this higher is the background - you don't need me to tell you what's wrong with it. Hanging the sheet farther behind your model if you don't want to use a wider aperture is the best way to go. Also, using more than one light (maybe one top, one bottom) can help minimize shadows.
Great expression on the face, and whatever technique you used here came off really well!! Can't quite figure out how you did it, which is a good thing :-)