![Rise of the Guardians mistake picture](/images/screenshots/198000-198999/198735_sm.jpg)
Continuity mistake: At the end of the movie, before the Guardians leave, Jamie rushes over to hug Jack. In the first shot, the top of his head nearly reaches Jack's ribcage. However, in the following close-up shot, Jamie is almost at the same height as Jack's shoulders. (01:27:30)
Answer: Jack is the guardian of fun. It's stated in the film.