This Painting Of An Egg Looks Like It Actually Cracks When An Artist Draws Over It

I can only accept two reasons as for how this drawing of an egg — yes, a drawing — looks like it actually cracks as an artist continues drawing: our eyes are pitiful things that cannot be trusted at all or the artist is a magician. There is no in between. This is expert level artistry that is very likely sorcery at work. Or the human eye can’t actually see a damn thing.