Chinese stealth technology
 

Can someone tell me how the Chinese developed these stealth chairs??? I can't figure it out. Also, how are the bells hanging? These are not camera tricks as they were performed live.
YouTube - [Shanghai World Expo Closing Ceremony Concert 720HD] 04 - Fusion of Art and Music

it is an old trick you often see in magic show.
The girl lifted from a table or levitation trick etc....
the girls are wearing some exoskeleton than can be locked by doing a precise gesture.
you need too a strong anchor into the floor.