She lip-synched the songs for the movie.
One of these was a musical guest slot on Saturday Night Live, which became almost scandalous when it was leaked that Simpson had attempted to lip-synch to a recording.
The bottom two contestants are then forced to compete in a lip synch battle to keep their place in the competition.
Based on their performance in the lip synch battle, the judges decide who gets to stick around and who is eliminated.
One of the show's viewers' favorite moments was when Shannel's wig fell off during a lip synch challenge.