Art is a difficult, subjective matter sometimes. I don't think we can expect everyone to "get" every piece of art. If the poster upthread wanted to, they could read more about the painting, in detail, where perhaps someone writes about various specific features of it and what people believe those features mean. Maybe that would provide more understanding, and they could feel his emotions that way.
I'm not saying they have to or should do that; maybe they just don't care enough. And that's fine. But the option is there.
If someone prompts an AI, "generate an image in the style of Picasso's Guernica", then the result of that, by definition, has no deeper meaning. No emotion went into creating it. The person who prompted the AI could make something up, but it's hard to say what's "real" there. Even if they were to guide the image generation by describing their own emotions, the result wouldn't really be their own expression of their emotions. It would be the AI's probabilistic guess as to what those emotions look like on paper, when rendered using Guernica's style, based on a mish-mash of thousands of different artists and art history research. Ultimately it just doesn't mean anything.
I accept the idea that a talented artist could guide the AI with much deeper specifics about what to "draw", how to draw it, etc. And maybe -- maybe -- that's something that would convey the human's emotions faithfully. But I don't think that's what we're talking about here.