What about the harm caused to me by the excruciatingly boring process of mindlessly making moves in a non-game that's already been won essentially? For me, this is psychological torture. Amid all this emphasis on harm, somehow you've totally overlooked my harm.
You seem to be assuming there's some implied moral obligation to play a game to the bitter end. There isn't. There's an option to concede, which implies that players have the moral option to concede.
The artist is presumably working alone and not imposing an onerous burden on anyone to complete their work.
A better analogy would be a baby in a highchair pushing his sippy cup off his food tray onto the floor. An adult picks it up and puts it back on the tray, whereupon the baby immediately pushes it off again. After a few rounds of this, the adult walks away, and the baby starts screaming and crying. Is the adult "harming" the baby?
You seem to be assuming there's some implied moral obligation to play a game to the bitter end. There isn't. There's an option to concede, which implies that players have the moral option to concede.
The artist is presumably working alone and not imposing an onerous burden on anyone to complete their work.
A better analogy would be a baby in a highchair pushing his sippy cup off his food tray onto the floor. An adult picks it up and puts it back on the tray, whereupon the baby immediately pushes it off again. After a few rounds of this, the adult walks away, and the baby starts screaming and crying. Is the adult "harming" the baby?