At the start of the movie when Jamie and Chris are at her graduation party and they are in her room, when Jamie first jumps on the bed she is rolling around and you can see her under wear. About a minute later she is tickling Chris and leans down towards his abdomen, and her butt is in the air towards the camera, you can clearly see she has on black shorts underneath her dress. Then another minute later she leans over again and there are no shorts!