Inside jokes for Disney animators in the 1990s were disguised Easter eggs. Anyone who witnesses a prank would propagate it via word of mouth. Nowadays, animators have to step up their game in order to better camouflage these situations as a result of streaming platforms and the ability to screenshot them.
When Aladdin asked Genie to make him a prince in “Aladdin,” animators buried a little surprise for him. It’s Sebastian from The Little Mermaid who Genie finds in a book he’s glancing through while hunting for a princely figure for someone. We don’t really pay a lot of attention while watching an animated movie so it’s obvious that we missed it