That is honestly very impressive. I feel like they must have had to use a ruler very very carefully down to the millimeter on some of this. The evenness of the pattern at the top and the ruffles on the couch in particular is just insane.
It's like someone got in a time machine and told them how software drawing would be like someday and they decided to emulate it.
They even got the idea of a limited palette and using dithering/etc tricks to appear less limited.