Toward the end where the guitarist comes to talk to the kid at his house. He turns the chair around to sit in it backwards, but throws the shirt down onto the ground. When he sits down the shirt is back on the chair.
Penny Lane picks up William to go see Stillwater at the Riot Club in L.A. In the very beginning of the scene in her car, a reflection passes up the windshield over William's face as they are driving. The Reflection is the prism and spectrum from Pink Floyd's "Dark Side of the Moon" album. There are no other reflections in this scene.