The guy who filmed this didn't have the best location or the best camera on his phone, but he did have one of the best possible girls to film. This girl is sexy, wants to make a spectacle of herself, and is wearing a dress just begging to be blown up. The air jet operator is happy to oblige her.
All the visible action is on the girl in the purple sundress on the left side. The saxophone player is blocking the view of the other side of the stage and the girls getting their dresses blown there.