You used matrix metering here and the picture exposed perfectly for the artist and washed out his art.
If you had used spot metering you could have exposed and focus on the art, exposing it perfectly. Then you could have pushed the A/E lock button to lock in that exposure. Then you could have recomposed and refocused on the artist, keeping that same exposure locked in. You would avoided that burned out art. The artist and the art at the lower half of the image would have been dark. But you could have used levels in photoshop to make it lighter. If it made the top part of art too light, you could have used the shadow highlight control in photoshop, which would have allowed you to make the dark parts lighter without making the light parts lighter, too.
