Could aliens be watching Earth on a time delay?

Yes — if aliens were watching Earth from far away, they would be seeing it on a time delay, because light takes time to travel.

For example:

• Alpha Centauri (about 4.3 light-years away): they would see Earth about 4.3 years in the past.
• A world or civilization about 500 light-years away: they would see Earth roughly 500 years ago.
• An observer 65 million light-years away: they would see Earth as it was 65 million years ago, long before humans, around the time of the dinosaurs.

So in principle, yes: any distant civilization looking at Earth would be seeing the past, not the present.

In practice, though, actually resolving surface details like cities or animals from those distances would be extraordinarily difficult. Most likely they’d detect Earth as a point of light and, if they were advanced enough, maybe infer things from its atmosphere or other indirect signals rather than seeing detailed imagery.

Exact capabilities would depend on the observer’s technology, distance, and telescope size, and those details can change the answer a lot.