Two people start a scene. They go for like 2-3 lines. Someone else freezes it. They add some stuff to the scene like a director. Additional characters, scene paints, layered on emotions, anything they want. Then the person who froze it makes a quick case as to why they think the additions are essential. Then two other people in the group approve (including the people in the scenes) approve it or they disapprove it. If they disapprove then someone else adds stuff from the original freeze point and starts the process all over again. If they approve then the scene continues with the additions for another minute until another appropriate freezing point and then your repeat the additions process all over again.

-- Tao Yang