Show not tell? Nouns not verbs?

The novel I'm currently listening to has "her eyes sad but resolute". The point-of-view is of somebody else, so the author knew that "She was sad but resolute" would be wrong, but giving eyes such expressive ability isn't the solution, unless the observer's analytical abilities are being mocked.

The same book has "she had a flirty smile on her face". Why the noun "smile" rather than the verb "smiled"? The phrase "on her face" is redundant anyway. Perhaps the answer is that with nouns you can use adjectives rather than adverbs, and "flirty" sounds better than "flirtily"?

Another book has "There was an audible trembling in his voice". I don't know why "audible" is there but I'm more puzzled by why the noun "trembling" is preferred to the verb "trembled". What's wrong with just "His voice trembled"?

Yet another book has "a scream came out of her mouth" rather than "she screamed". Perhaps there's an attempt at distancing, of making the scream more real by making it into an object. A potential advantage of this construction is that extra verbs and adjectives can be used - "a stifled scream burst from her mouth" maybe.