It's a variable width font, so it can be smaller than a fixed 3x3 font. For example it chose this (ambiguous) encoding for "o": -- xx xx -- where a bigger

It's a variable width font, so it can be smaller than a fixed 3x3 font. For example it chose this (ambiguous) encoding for "o": -- xx xx -- where a bigger 3x4 font could choose the overhigh and wider -x- x-x -x- ---