He's looking in a mirror, so left and right are reversed.
For some reason I have a hard time painting collars and lapels. So I'm always looking to see how other painters handle it.. So many years ago I'm looking at this painting and the coat is bothering me. For one thing he's wearing a ladies coat - buttons on the right - and it just looks awkward to me, out of scale etc. also the door jam is slanted and the sky not painted in, on the picture hanging on the wall - just a single thin brush stroke for the picture frame. It's as if he was in a hurry and a lot of pain. Not bothering with the background or "fixing" the coat - just painting it "as seen" in the mirror. -- which means the opposite ear was the one he actually cut.
Here he is with another self portrait. Van Gogh is right handed, but again painting from a mirror, it's reversed so he' holding the palette instead of the brush in his right hand. But this time he's
not in pain so he does a good job rendering the coat and puts the buttons on the correct side for a man's coat.
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