Let's take it to the extreme - if you randomly outputted noise as a picture, that picture is not copyrightable (or ditto with random letters/numbers and printed it as a book).
It feels to me that the copyright office is using this similar line of logic, to make the claim that the resultant work is not copyrightable if it was wholly generated using _only_ a prompt and an AI.
It feels to me that the copyright office is using this similar line of logic, to make the claim that the resultant work is not copyrightable if it was wholly generated using _only_ a prompt and an AI.