Why can't they just make a fictional universe?
Before each Disney film, you see Cinderella's castle with fireworks, a train that runs through it, and a pirate ship on the river in the distance. It's as if the Magic Kingdom were an actual... Magic Kingdom, and not at all some theme park in the real world.
Now, fit in the Tree of Life, and you have an exciting idea for a movie. How about Cinderella's honeymoon, except it ends up getting ruined by a villain, and she and Prince Charming fight the whole time as they travel through the fictional equivalent of the theme park worlds. And in the end it gets better.
A sort of happily? ever after kind of breaking the 4th wall into another stage sort of universe.