When Stacy confronts Barb on camera backstage, the monitor above their heads appears to flip the image, but it's not a monitor, it's the back of the projection screen from the main televised image that is the centrepiece of the Kippie Kann Show stage's back wall.
Stacy is talking on the phone and faints after when Carly Simon walks in. Carly picks up the dropped phone and begins speaking. When Stacy comes to, Carly says "She's coming around again." "Coming Around Again" was a top 40 hit for Carly Simon in 1986.
When Carl, the producer, confronts Stacy on the final show, she tells him: "It's my life". Carl's answer was "It'll be over soon". The actress, Brittany Murphy died just 5 years after that movie, at the age of 32.