I found the below on a site called Art Effects, their slogan is "We Put The Trick, In The Trompe Of Trompe L'Oeil"
Take a look at both the Dartboard and the scoring tablet above. Both of these are painted on the wall.
Now look at the top photo again. You will notice the final dart in the illusionary coffin so to speak. It is stuck in the wall, see below.