[jasrys]

Sure. In an infringement lawsuit involving a fair use defense, courts will apply the "four prong" test [1] to determine whether or not such use is indeed fair use under copyright law. The first of the four prongs, the "purpose and character" of the use, is also known as "transformativeness." The Goldsmith/Warhol ruling (to simplify) said that Warhol's changes to Goldsmith's photograph were not sufficiently "transformative" even though they contained new expression (adding orange color etc.) because the end result effectively competed with the original photograph and therefore did not qualify as a fair use.

Right, your backwards movie example would fail the fair use test too. Nothing's really added, there's no new expression, it competes with the original, etc.

[1]: https://fairuse.stanford.edu/overview/fair-use/four-factors/