When Ray comes to Robert's apartment to convince him no one thinks he's gay, Robert takes out a bottle and holds it on the counter. When the camera angle changes, it can be seen that he is taking a sip, with no time to raise it to his mouth.
When Ray, Frank and Marie discuss the possibility of someone in their family being gay, the open spout of the milk carton is alternately pointing at Frank or Marie, even though no one moves it.