I think different people mean different things by "see the pixels." I can't imagine being able to see individual pixels on a 15" 4k display at laptop distances,

I think different people mean different things by "see the pixels." I can't imagine being able to see individual pixels on a 15" 4k display at laptop distances, but I can imagine being able to notice minor distortions in the outlines of text, or more discomfort than necessary when reading small text, as a result of lower pixel densities. That could be reasonably described as seeing the pixels.