Sorry, forgot about that thread. If we would see a grid diffraction pattern, the pixels could not be visible at all. You cannot have interference between adjacent pixels if they are resolved in the image. You see light if two conditions are satisfied: (a) the direction is right for light coming from the pixel (it is a camera/eye observing the pattern) and (b) the angle is right for positive interference. The last picture is not from an extended grating, it looks like a double-slit or maybe triple-slit pattern. Otherwise the maxima would be much smaller and sharper. I tested it with some more monitors. Some show nice patterns with variable angles, some do not show a pattern at all.