Great placement for your Hidden Faces entry. Certainly meets the challenge. You got many comments during the challenge and I really cannot add to much to what's already been mentioned.
I agree with many of the comments on the rotation only because that makes the face a bit easier to see. I think the comments on moving it more in the center are also about making it easier to locate the features. As a general comment (not connecting the shot to the contest but as a stand-alone photo) I find the cropping too tight as it cuts off parts of the "mouth". I know that sometimes tight cropping is a must as it eliminates elements that would destroy the "face"
Adding color or warmth through light would be a good thing to play with if you wanted to. This may have helped add an interesting element.