“A Great Opportunity”
The worst kind of free artwork is graffiti. You could paint over it, or you could hire a professional artist to create a beautiful mural to mask the graffiti and attract people to your establishment. Or, and this is the route this person chose, you could offer nothing in exchange for a huge mural on the back of your building.
The good thing is that this person mentioned that no money was offered, so artists knew immediately to ignore the post. Even if you did find an artist who’d work pro bono, you’d have to at least supply the materials, and we know you wouldn’t dream of doing that.