Gardiner's G-1 and G4

The A-3 is trying to convey the sound made in English denoted by the letter A. The 3 is representing an "ah" sound. When one sees the Egyptian vulture, often painted in greater detail than this typeset, and sometimes abbreviated in text to a few curved lines, one reads the sound "aye" or something close. Nobody really knows for sure, but it's a very good guess and it works with a good many linguistic cross references.

So there you have it. You can see how it is that when this typeset is shrunk, say, by half, the differences between them are obliterated.  Do you even notice the differences? The long-legged buzzard has a more rounded head and breast and a  tail feathers more squared. This is more evident in larger paintings with more detail.