Its a common chant. Before it was a common chant like "We wanna see -- Henke(for ex.) wave!".
Now it have transformed to "We wanna see -- Henke(ex.) dance!"
A big newspaper had created a air balloon behind the scene. When Henrik where interviewed they took the airballoon up in the air with a banderoll that said "We wanna see Henke Dance!" and 40.000 started chanting.