When Stanley goes proving Dr. Neuman the bizarre effects of the Mask, he does a strange dance trying to start the metamorphosis. Watch carefully Dr. Neuman's hands in this sequence: when Neuman is shot front, he's holding a pen with BOTH hands at mouth level. Neuman is seeing from the back (watching Stanley) and we don't see his hands (of course his hands are supposed to be resting on the desk). We can't assume that he is rising or lowering his hands because the camera angle changes are continuous.