How did the artist put the QR code on the painting? Did he also painted that one out? That interest me a lot since that is not a digital product or a printed one.
I'm also curious on that one. Based on the painter's statement, he "placed" (not "paint" too) a QR code in his painting so I think that one is a print out. QR code is very sensitive so if he really painted a large scale of his own and put it on his graffiti then I might say that he is really a well-skilled painter 
. Did you already heard something about prayer service for exchange of btc? Yup! You heard it right. I'm not sure if this is considered a creative way of earning btc but its concept never fail to astonish (with a little bit funny thoughts) me every time I think of it
. Check it out: https://bitcointalk.org/index.php?topic=4632723