A retina display's claim that individual pixels are small to see means you're not supposed to be able to distinguish individual pixels in an image - so curved l

A retina display's claim that individual pixels are small to see means you're not supposed to be able to distinguish individual pixels in an image - so curved lines appear smooth without pixelation. It doesn't mean that a 1 pixel-wide line is invisible, or that you won't see a single white pixel on a dark background.