The Trailing Adjective (or Adverb)
He was living in a large complex, very depressing.
I'm pretty sure those ending adjectives are ungrammatical. I have no idea how long authors have been doing them, but I just started noticing them recently. So I will include them in cutting-edge.
We're not ninjas," I said, sour.
I could see that she was smiling, faint, but enough to ....
(All from A Grown-Up Kind of Pretty, Jackson)
Part of the structure is the preceding comma. There can be a preceding period instead, but then it looks like a non-cutting-edge fragment.
They follow SePG, and they are meaningful in an obvious way. They are, obviously, useful. So it would be expected that they will seem normal, in 10 or 20 years, or however long that takes.
I smile at him, embarrassed and happy. "Thanks."
Um, that's basically a misplaced modifier; hopefully it is clear that it is about her. That would be assuming the reader knows this construct and starting to treat it like a convention.
This can also be done for adverbs. I will include them as part of this new construct.
I consider her question carefully, thoughtfully.
The carefullytrails in the normal grammatical way. No idea why it doesn't precede the verb. In a sense the trailing adverb was needed only because the sentence already had an adverb. Note that, in the mysteries of grammar, we can write the first two but not the third:
I thoughtfully consider her question
I consider her question carefully
I thoughtfully consider her question carefully