Right, so you might want ask about this on !askscience@lemmy.world or such, as science-y folks tend to not be comfortable with what I'm about to say, but to the best of my knowledge, that's all just complete horseshit. Like, no, your understanding of the photograph is not somehow incorrect. It's just two halves of a photograph and because you know the first half, you know what's on the second half. The second half does not get changed by you looking at the first half. Nor does the entangled quantum get changed by you looking at the first quantum.

I think, a big part of this mass confusion is that at the size that quanta have, looking at them does actually change/move the quantum that you look at (not a potentially entangled one). This is not for crazy reasons, but because looking at them requires light, which is the equivalent of blasting them with photons, and photons are themselves quanta.
It's like if you had a dark room with a ball in it and you can only throw other balls into there to try to figure out where the first ball is. You need to hit the first ball, in order to have a chance of working out where it might be based on the angle that your thrown ball returns at. If you do hit the first ball, it will move. So, you only really know where it was at the time of impact. Quanta are not balls, but they do still interfere with each other when they get close to each other.

Entanglement in this analogy is that you've spun up two balls next to each other like cogwheels, so you know them to have the opposite (and equally strong) spin. Then you've released those into the dark room and start throwing other balls at them to try to work out their spin. If you hit one of the spinning balls, your thrown ball will come back out with a spin opposite to that and the spin of the ball that was hit will have reduced. In this moment, you know that the other spinning ball also has an opposite spin, because you originally spun the two balls like cogwheels. The other ball does not get changed by you measuring the first, but there's no way for you to know, because you have to measure it to find out, which means also throwing a ball at it and therefore changing it, too.

As far as I can tell, this is the other big part of where the confusion comes from. Because measuring necessarily also involves changing the thing and because it's actually impossible to disprove that the entangled quantum didn't get changed by us measuring the first, you get folks that follow a school of thought of things being non-deterministic. Of things only being set in stone once you measure them. There's lots of vested interest in things being non-deterministic for religious or moral reasons and there is no way to disprove it at the quantum level. These folks then propagate concepts like superposition and that when you open the box, you're the one that forces the cat to be killed. (Schrödinger was not one of them, by the way. The cat analogy was a critique of superposition as an idea.)

To my knowledge, there's no evidence for non-determinism (folks will sometimes argue with quantum fluctuation showing it, but it doesn't happen in complete isolation, so that disqualifies it in my opinion) and given that the rest of our reality seems to be perfectly deterministic, I think we should assume the quantum stuff to be like that, too, unless proven otherwise, but unfortunately not everyone goes along with that.