The undo and redo icons can be used to revert or repeat the last change made to your image.
Click the back arrow icon to undo.
To undo a change made to your image, simply click on the backward arrow icon to backtrack.
Image will revert.
The image will show the version prior to the last edit made (in this case, the undo operation removed an image rotation).
Click the forward arrow to redo.
If you preferred the change you made before backtracking, click the forward arrow icon to revert the image (in this case, the redo operation will repeat the image rotation action from earlier).
Review and Submit to save.
Once you are content with the changes, click the Submit button to save the image.