Yeah, I mean, slop is easily recognisable by structure and content. But the obvious "markers" everyone claims (emdashes, hyphenation, etc), are just the writing style taught in the predominantly ex-British-colonial schools where the labellers were educated
The human element cannot be recreated because the human element that created the beast becomes further removed and only the beast remains.
I say beast to provide a tell that what I write is 'human'.