TL;DR for AI writing warning signs:

• Use of the em-dash (—)
• Parallel sentence structure (e.g. "It's not just X, it's Y")
• Grouping things in threes or at least odd numbers
• Delineating line breaks with emojis
• Odd/unnatural verbiage
• Overuse of filler words (talking like your average LinkedIn post)
• Exaggerated and empty praise
• Weird analogies and similes
• Restating and overclarifying points

TL;DR for signs something was written by a human:

• Including anecdotes
• Written in the first person
• Tangents and nonlinear storytelling