As a kid who watched this in the theatre, I can tell you my eight year old brain that knew from reading comic books that Superman travelled in time by flying faster than light, that we are watching the Earth from Superman's perspective.
That's what I saw. I didn't see the earth's rotation reversed. The final moments when Superman appears to change direction makes sense, as he had achieved the speed to travel back in time, made sense to my kid brain, as he now he had to fly back into normal time ie change direction from going back to forward, like I would a video recorder.
What we see is the flim reversed. Literally. The SFX scenes played backwards, for a kid coming from seeing the original Time Machine movie, it was exactly the same way time travel was shown in that oscar winning sequence ie the Time Traveller sees the events around change in time lapse film fashion. Same here but in reverse.