El Mantador (PLAYER)

[Chris2Balls [:B]]

I can only talk for my own portrait, but I used the dithering to convey cross-hatching: if the cross-hatching is very fine, but light, then it wouldn't be black, but a lighter colour that would blend slightly - consider it sub-pixel cross-hatching. The size the dither patterns is an equivalent to the length and the interval of the cross-hatching.
I'd say the dithering in that case is more of an "inking" technique rather than a "colouring in" technique.