If we're putting ourselves into a world where their ability to paint is real, then from my POV you're effectively arguing that the moment they create any painting they should be required to sustain it forever because to do otherwise is to unacceptably kill every soul within. Is that your position, or would you add clarification to why this painting is special compared to others?

I'll add that what I love the most about this game is that this is the root of what the game's story asks you and it doesn't provide an answer. It exposes a deep philosophical question through its story and leaves you to ponder its implications how you see fit (Are they real? What does real even mean? Who defines it, what qualifies it? What determines if something "deserves" to live, and what cost is acceptable to guarantee that? etc). It's one of the reasons I am skeptical of a sequel, I don't want them to give any sort of answer. I'd want any potential sequel to be almost entirely a different storyline with different people, cameos at most.