You don't even need an algorithm, just research what the human authors say about their work and specific points which the reader values high in them. Quite often you will figure out that it's just random s** they wrote together to get something done, without any deeper meaning. But people make up some meaning because that how it works for them, makes it better.
The art is on the perception, not the intention. Though, if they overlap, it's more satisfying.
Human creative works are art not because they have "deeper meaning", but because they reflect the humanity of their creators. Whether an author writes a multi-layered novel built around a complex philosophical idea, or just light reading for entertainment, has no impact on that fundamental essence which makes art what it is. Not all art is great, but all art is human.
That's a tautology. Human creative works by definition reflect the humanity of their creators. AI creative works reflect the humanity of its training set, which eventually may be indistinguishable.
As for all art being human, there are a lot of birds who make art to attract a mate in nature, and at least one captive elephant that can paint.
The art is on the perception, not the intention. Though, if they overlap, it's more satisfying.