Chris is correct.
They are pretty sticky about this and photography of any kind.
We spotted a lot of people trying to take pictures of there group before the preformance started and were asked not to. However the Cirque employees (selling programs inside the theater) were willing to take peoples picture, although they were watching to see who was watching them do it - like they might get in trouble. The Disney employees, ushers, ticket takers, etc. were sticking to the rules about photography.
I would suggest buying the video or (maybe they have DVD) after the show.
Plus they have so much going on you might miss something if you had your eyes behind the camera. Things are happening all over the place. Enjoy!