The first shot of the curator putting a phone handle on its receiver is flipped horizontally. Notice the handkerchief in his pocket is on the wrong side. Also this shot is taken from the end of the scene in which he calls Duce later on in the story.
When Michael Nesmith says, "Oh, nobody but a fool would paint in the basement!", his lips are actually saying idiot instead of fool.
In the first scene following the opening credits, when Duce stops Chuche from hitting Peter Tork, a piece of camera equipment pop into frame from below. Also, in the background two chalk marks are visible on the floor to indicate the places for the next piece of dialog between Duce and Chuche, who immediately move on to these marks.
When Liberace is smashing his piano, Michael Nesmith can be seen falling over, cracking up laughing in the background in some shots.