When Heather talks with Diane about her dress, her left hand is raised above her head and touching a bookcase. In the next shot both Heather's hands are clasped together.
In this episode we see that the door next to Dianne's front door opens into the kitchen. In the first episode o the season. Power Play (1983), that door opened into Dianne's bedroom.
Sam is supposed to be an on the wagon recovering alcoholic, but he pours three glasses of wine at Diane's spaghetti dinner. One for Diane, one for himself and one for Markie Post's character. However, as this is Diane's apartment and she cares about Sam's condition, she obviously uses non-alcoholic wine.
The light in Sam's office is never on, even though a dog is supposedly being kept there, but there is no specific reason for the lights to be on.