I think we may be talking about two different concepts regarding creation of art.

Absolutely humans (and myself, I'm a professional illustrator) use a mental patterns to come up with ideas.

The physical difference in AI generation is the lack of butt-in-chair time of the flow state. Painting/drawing/rendering art is not just mindless time to be compressed; it's a mental/physical/emotional/(and some would say spiritual) flow state with a lot of "input" abstractions beyond the patterns. Things like the creative's personal mood, personal past experiences, recent discussions with friends, recent texts they read ... those all fold into it. I wouldn't trade that flow state for the world, and it absolutely leaves fingerprints in my creations.