Showing Off on the Dance Floor

What does this mean ? I hear people who are just starting out or don't dance that well always complain about Salseros showing off on the dance floor . What does that mean does that mean people are doing moves that they can't or wish they could do? I am curious on why people say this . When I dance, I try to express my self the way the music makes me feel. I never looked at a dancer on the floor and thought one was showing off, but that's just me .

I see Shaka and Psyon rolling and I say to myself those guys can roll,the thought of them showing off never comes to mind. Again that's just me