I have just recently bought a 4k hdr 55 inch tv (Vizio P55 F1). Here is photo of brightly lit pixels from https://www.rtings.com/tv/reviews/vizio/p-series-2018
Picture shows that pixels are clearly squared and uniform
Often when I look at uniform color on the screen (think Playstation menus, but in the real-life videos as well), I see that on various mid-bright spans of same color pixels lit in a chessboard pattern instead of uniform.
On the last image white letters seem more or less uniform, but grey background is definitely not. I draw 2 green lines - top one is going through green subpixels that are brightly lit, and bottom one is going through green subpixels that are dim. Same goes with blue lines, and same goes with red subpixels.
When I get a 4k screen and output a 4k content to it, I expected it to be displayed pixel by pixel, but that is obviously not the case (or is it PS4 generate this patterns by itself?).
I couldn't find anything about it on the internet because I was not able to find proper name for this effect.
I must add that I just recently saw a tv that doesn't have this effect, but I don't remember the model.
My question is - what is the name of this approach, so I can read about it and understand the reason behind it?
Bonus questions - what is the rationale under it? Is uniformly lit tv is better or worse? Is it generated on the source of signal (ps4) or on the tv?