Other mistake: During the musical auditions, the pairs audition doesn't start until halfway through the auditions. But the disturbing dancers were a pair audition and Ryan and Sharpay were the only pairs.
Other mistake: When Sharpay is looking for Gabriella in the girls bathroom, she walks past where Gabriella is hiding behind the wall. It is also shown that there is no other room behind that wall. When Sharpay turns around to walk back out, it is impossible that Gabriella couldn't have been seen by Sharpay as she would have been in direct line with her vision. (00:48:45)
Other mistake: On the clock that shows 12:05 (just before the basketball team and the science club start their coup) the second hand isn't moving.
Answer: Well at the start she was just doing it for fun and because Troy was doing it. But as they went on she just wanted to get the role because it would have showed the school that she wasn't the freaky geeky nerd girl. So she put out all the thoughts of the audience till they actually had to be there.
Movieman123