Okay, I didn't actually see the movie, as in, "take in the film with my own two eyes," but, from the thousands of commercials and the South Park rendition of such, I think I have a pretty decent grasp on the concept:
You dance good, but don't smile, then you're "hard," but not in the sense of being able to have an erection or sexually pleasure a female.
I ask this question: WTF?!?!?!?!