For American Graffiti. The clouds and sunset were added they were not originally there. The original shot was different. Its a minor change honestly, especially considered what he did to Star Wars and THX 1138.
Oh, I thought you were referring to the sunset shot in THX, haha! Yeah, on the one hand it’s a shame that even American Graffiti, a non-special effects driven film, had to be meddled with by George on all the digital releases, but on the other hand it’s such an inconsequential change that it doesn’t negatively affect the film at all.