A few things...
One, there isn't a black "pixel" - the black is the space between pixels. Minor issue in your drawing, - I still get your point.
Two, there are two dimensions you'd have to work with as the black space surrounds each pixel. You could use two such mirrors - one to cull the horizontal black fill lines and one to cull the vertical black lines.
Three, how would you ever manufacturer something like this?

Seems way beyond the mfg. capability of the DIY crowd. Seems like a reasonable concept, but not something anyone could actually build.