So what happens if the universe is expanding? It seems to me our holograms would change positions. Perhaps this explains what we perceive as movement. The edge of the universe moves, and suddenly I think I'm driving my car someplace.
The other thing that might happen is that our images would grow in size, the same way a projector's image grows as you back it up from the screen. We wouldn't notice the growth because everything would grow at the same time, with denser objects growing just a bit faster, thus creating the illusion of gravity.
If any of that seems inconsistent with scientific observation, don't worry. The great thing about being a hologram is that our memories of the past are all false. So if you think our planet orbits the sun, maybe you only remember learning that and it never happened. All bets are off when you are a hologram.
If our memories are false, you'd expect to see some inconsistencies in the historical record, just because all those false memories wouldn't fit together seamlessly. The longer the history, the more likely there would be inconsistencies. For example, we might have a popular theory that the universe suddenly inflated from a dot of nothing, or that most of the universe is made of invisible dark matter, or particles can have spooky entanglement issues from a distance, or light can behave like both a particle and a wave. Check, check, check, and check. You're sure those things will be rationally explained by science someday, but I'll predict new inconsistencies will be formed in the process, to perpetuity.
If our reality is a hologram, you might also expect that the theory of evolution would have some head-scratching parts. Maybe something like this:
If you are tempted to argue that I'm misinterpreting something here, based on your vast knowledge, remember that your knowledge is all false memory. Or maybe just half vast.