During a scene with Danny and Jordan discussing product placement in their show, Danny walks to the end of the hall to get a Snickers bar, an example of how products get incorporated into shows in the middle of a scene critiquing exactly that.
The ladies' dressing room contains a "Bartlett for President" poster, a reference to Sorkin's previous show, The West Wing (1999). The poster appears at time stamp 21:37. Simon and Tom are trying to talk Harriet out of posing. She crosses to a small gallery area to wash her hands. The camera switches to show Simon from behind in the right foreground, Harriet in the background. The poster appears on the wall to the left hand side of the screen for a few seconds.
Good series continuity: Matt and Danny's scene discussing "Quentin Tarantino's Hallmark Movie 'Turkey Won't Die'" shows their scheduling board, listing sketches mentioned in the 2-part "Nevada Day": "Judgmental Credit Card Rep", "Lifetime TV Movie Awards", and "Cheeses of Nazareth". Also supposedly performed are: "Commedia Dell'Arte", which would be at least the third installment of Jeannie's project; "Jenny Doesn't Want to Have a Baby", which was dropped from Lauren Graham's show-hosting after dress rehearsal; and several others not mentioned in the series.
Matt's note of a sidekick is a direct reference to the first appearance of Robin in Batman comics. The character was originally created so that Batman was seen as less crazy, talking to a partner instead of rambling to himself.