B was probably thinking "Yeah, if I give them a little taste tonight, I'll make them watch me at the Oscars in two weeks."
I've seen her perform that song better on Oprah.
I agree that on the red carpet, Jennifer's dress look better. But those girls got a mind of their own. And at least on Queen's dress, the girls weren't running away.
BTW, this isn't Mary's first time winning. This is her first time winning during a broadcast. For some reason, her and Mimi don't get a lot of love from the Grammys.