In this particular case I think it was fairly obvious, not so much because of the meaningfulness of the human-written poems (though the poems that were written

In this particular case I think it was fairly obvious, not so much because of the meaningfulness of the human-written poems (though the poems that were written by humans did clearly have meaning associated with them), but more because the machine-written poems were very awkward. Sonnet 1 was about a person mourning their mother who died in a car accident. It read well and made sense, so I would have been very surprised if it were written by a machine. Sonnet 2 didn't make sense, but more than that there were very awkward constructs. Rhyming "drawer" (the furniture) with "door" and "drawers" (the undergarments) with "floors" in the same quatrain reads very poorly. "Sergeant" does not rhyme with "apartment". Sonnet 3 was about something (a growing plant), and it reads well, so it was written by a human. Sonnet 4 was about something (Joy, a personification of the emotion), and it read well. "Joy" being consistently capitalized throughout was a subtlety that convinced me it was written by a human. Sonnet 5 had more awkward constructs. "Shame" and "Tame", "Inflame" and "Came" in the same stanza. "Bring" and "wandering" don't really rhyme. The last stanza is just weird -- "hear" is supposed to rhyme with "cheer", "cheers" (which is the line right before "cheer"...) is supposed to rhyme with "roars" (?), and "nights" is supposed to rhyme with "respects"? Again, it didn't really make any sense. Sonnet 6 was similar to Sonnet 3. It's about something (a growing plant again), and it reads well again.