What do people mean when they say a blu-ray 'looks compressed'?

[raymanfan]

When I think of video compression, I think of prerendered videogame cutscenes like this:
https://www.dasm.cz/img/recenze-max-...ene-detail.jpg

Like, so much compression that each block of color is distinct and visible in the background.

When people say the original Predator release, for example, had heavy compression, do they mean the same kind of thing and my eyes (thankfully) aren't attuned enough to spot it while the film is in motion? Or does compression in this sense take a different form visually?