Formal diction is what most modern poetry resembles.
They told the coach last night at the game. The coach taught us a new skill.
I haven't read this essay but imagery is quite easy to find. Imagery is usually exposed by finding explanatory words or words that make is easier to imagine the event in a story. For example, "The sun was shining a fierce red. It was a fire blazing through the sky." Sorry if I can't give you an exact answer but atleast you know what to look for. I hope this helped you.