YOUR IMAGES
Go back to an earlier version
Redrawing an image (with fewer colors, for one) makes a new VERSION beside the first: a version never changes, so going back is opening it. The pill beside the title says which is open, and how it differs.
Free · no credit neededWhere are an image's versions?

Press the pill: every version of the image with its picture, what changed and when, the open one checked. Below them, compare this version with another (the canvas's split, the other on one side), or see the image in your library.
Is there a key for it?
Yes: [ opens the version before, ] the one after, wherever you are on the result.
Does a new version cost a credit?
No. A new version is free, and once an image is unlocked, every version of it downloads in every format.