She was awesome. I don't think it was staged. I think that she probably planned every little detail of how she was going to look, what her sign said, where she would position herself, etc., to maximize her chances. And it worked. I think Bono recognized as much, because as he was pulling here up, I swear he said something like "OK, you", in a playful, exasperated voice, as if to acknowledge all the work and prep and anticipation on her part.
Great job belly dancer girl/woman!