Apparently the concepts that became most Pixar movies were all thought of over a single lunch in the back in 1994.
The two guys behind this video happen to think that they also came up with the idea of placing “Easter eggs” (aka secretly hiding reoccurring characters & objects in their movies) during this meeting too.
The reappearance of the Pizza Planet truck from Toy Story is obvious, but I really can’t tell if that’s Wall-E in Toy Story. Hell, if you told me it was a trash can I’d believe you. Just because Nemo made an appearance in Monsters Inc. doesn’t mean that Wall-E was digitally designed back in ’95.
My theory is that all the Pixar movies occur in the same world, although the stories may be at different times. I wouldn’t be surprised if some of the people from The Incredibles can be seen their next movie Up! when it’s released next year.
And I don’t think it’s done solely for these “Easter eggs” but rather to save money and time.