Continuity mistake: At the pre-prom party, the head in Kelly's glass of champagne disappears. No time has passed, so it hasn't gone flat. (00:25:45)
It's a Totally Happening Life - S3-E16
Visible crew/equipment: When Brenda and Dylan are in the same bedroom and the camera is panning about, you can see the end of the set in the upper left corner. (00:18:35)