Disney's 1938 patent fixed it with one move. Guess which.

Push a camera into one flat painting and everything grows by the same amount, the moon too. A real moon never does. Cartoons were shot flat, and to move in, artists had to draw "a large series of backgrounds, each background drawing depicting a step forward". William E. Garity's patent for Walt Disney Productions splits the scene onto five planes under a camera looking down from 8 to 12 feet. Near planes rush past, far ones barely move, but the moon still grows, only less. So as the camera comes down for a close-up of "a person sitting on a bench beneath a tree", the plane carrying the moon "may be moved away from the action so as to prevent the moon from growing unnecessarily large". An operator on every plane, settings "to a thousandth of an inch", and the camera fires only when every operator has locked in. "Ordinarily clouds do not get larger just because you travel towards them."

Our own night scene, built on the patent's own example, with sizes from the patent's spacings; no frames from any film.

What would you have moved: the camera, the moon, or the painting? Comment your guess.

Sources: William E. Garity, assignor to Walt Disney Productions, US patent 2,198,006 "Control Device for Animation" (filed 1938) and US patent 2,281,033 "Method of Producing Animated Photoplays" (filed 1939).
Sounds: our own, made in code (earshot, CC0).