I've got to commend you - it took a pair to enter this shot. Of jeans, that is :-) That aside, I'm not sure what emotion you were aiming to convey. Although the act itself would be interpreted by many as sexy, the feeling is more utilitarian. Which maybe was your point. Fingers look a little oversharpened on my screen, but the focus is dead on. Interesting entry!
Trying to think about why this should score so low.
It's not frighteningly original, maybe, which would be a reason not to score high, but low?
Too many good shots in the challenge is always a problem (people are so inconsiderate, sometimes).
The fingers and fingernails probably needed to be sharper for the voting crew around here.
Shame - the denim itself comes out really well. Keep yourself a good copy and be content with that. I think most of all you fell foul of the pin-sharp convention.