From an outtake instead of the actual movie. Sharpay drives up in a pink golf cart, Troy gets in and then....it won't go. So Troy gets out, gets on his knees, and starts pushing it.
"Creme brulee." It's funny for being random. Where did Zeke get that?
From the first movie - the basketball team's shirt message for the Drama Club. And Ryan's attempts to read it.
Troy loudly and proudly proclaiming the exclamation point that he has on his shirt.
When Chad tries to get Troy to see how his wanting to sing has making the whole school go crazy and he uses Zeke baking as an example. Instead of being surprised by it, Troy is surprisingly excited about it and asks what it is that Zeke's going to be baking. They get a couple lines of dialogue about it, until Chad interrupts them.
The "weird kids" from the first movie audition for the play by speak-singing "What I've Been Looking For", and doing an abstract dance. Miss Darbus calls this performance, "very disturbing", and advises the weird kids to see the counselor.
The facial expressions during that scene. Kelsi's completely confused, Ryan looks like he is in disbelief.