Other mistake: Season 1, Episode 1: "Hot Tub". Just before Toot starts her earthquaking Charleston, look at Spanky Ham in the background; for a few seconds, his eyebrows are missing.
Audio problem: During the booze party, Toots sucks up alcohol from a tube while the others chant "Suck". But when this word is chanted for the last time, the characters neither open their mouth nor do they move in rhythm to the chant, as they did before.
Other mistake: Season 1 Episode 1 "Hot Tub" When the characters stand all together in one frame at the end of the introduction, zoom in on Princess Clara; here she definitely misses her eyebrows.
Answer: She was in the show 90210, so I'm guessing it's a reference to something she did in the show?