This is hilarious. This does nothing for you.

If I were a gym owner this douche would be fired and the other douche would have to find another gym just for listening to this idiot.

Mick, who said this does nothing for you, obviously know nothing about weight lifting or working out. Although this is fairly extreme, doing exercises, such as this one (a squat) while on a stabilization ball can be very helpful in both working on strength (targets many more accessory muscles) and balance (obviously), which is great if you're trying to improve your working strength (the strength you actually use when playing sports).
Funny picture though.