It's no secret there's an ever increasing presence of the wildly succesful Pixar films in the Disney parks, especially Disney's Hollywood Studios. If you've had time to check out the curent meet-n-greet location for Monsters Inc characters near the Backlot Tour exit, you may have noticed an inside joke among the Pixar staff.
While waiting in line for your chance to meet Mike or Sully, you may see postings in the queue area that look like a bulletin board with various notes and clippings from the various people that work there. One of these postings is a note from "Pete D" that reminds all employees, "No more jokes about Jonas please - too easy!".
"Pete D" is Pete Docter, director of Monsters Inc and Up. Jonas is referring to Jonas Rivera, the producer of Up. The joke is simply a reference to Jonas and for fans of Pixar films, it shows the good humored joking both of these animation legends can have fun with.
Thanks to meeko_ for the photo of this note!