Great concept, great composition. My only concern is that the desaturation of this shot has made it more bland than it could have been otherwise. Just for kicks (assuming this was a color original), instead of simply desaturating it, try stripping out two of the RGB channels (whichever two leave you with the best tone), then convert back to Greyscale from multichannel. The face may also be a little contrasty, but that could just be a result of the downsampling to post.
I dont know what's wrong exactly with this one to me, the face isn't in focus? the background should be more our of focus? nothing is in focus? Maybe I cannot point where the focus plane is, to me it should be on the models's face clearly.