This is a better article than the initial paragraphs reveal.

The author is saying that what James Joyce called ‘proper’ art is essentially a stepping stone for our understanding of the world and ourselves. And if that's true, it could possibly be a candidate for human exceptionalism, and that would be a differentiator between AI and humans, where AI can only mimic what has been done -- up to this step but no further.

Unfortunately, the author is a poor lawyer and argues against his own case. One exhibit is Rothko. Yes, Rothko was important in expanding our ideas of color and composition... but he did that through such works as a big red square. Could silicon randomly generate a big red square? Yeah. So where is that line? Sometimes it's our interpretation of a work that moves us forward, more than the work itself.

Which means humanity invents humanity.