In most self-portraits it is the face that dominates: Cezanne is a pair of eyes swimming in brushstrokes, Van Gogh stares out of a halo of swirling darkness, Rembrant looks relieved as if he were taking a breather from painting The Blinding of Sampson.
But in this one Goya stands well back from the mirror and is seen posed in the clutter of his studio addressing a canvas tilted back on a tall easel.
He appears to be smiling out at us as if he knew we would be amused by the extraordinary hat on his head which is fitted around the brim with candle holders, a device that allowed him to work into the night.
You can only wonder what it would be like to be wearing such a chandelier on your head as if you were a walking dining room or concert hall.
But once you see this hat there is no need to read any biography of Goya or to memorize his dates.
To understand Goya you only have to imagine him lighting the candles one by one, then placing the hat on his head, ready for a night of work.
Imagine him surprising his wife with his new invention, the laughing like a birthday cake when she saw the glow.
Imagine him flickering through the rooms of his house with all the shadows flying across the walls.
Imagine a lost traveler knocking on his door one dark night in the hill country of Spain. "Come in, " he would say, "I was just painting myself," as he stood in the doorway holding up the wand of a brush, illuminated in the blaze of his famous candle hat.