The cover art of 'Fast Forward' is based on a late 19th-century wood engraving known as the Flammarion engraving.

Several versions with added colour have subsequently been created, and apparently the one below was used. It was flipped over, probably to better match the 'fast forward' shape. If you look closely you'll notice some other changes: the tree has been removed, the heavenly 'machinery' has been rearranged and at the bottom the drawing has even been extended beyond the original.