1) its educated yet opinionated
2) it has a tone of disgust toward injustice, comparing it to an oozing sore
and its mood is that of a call to action.
hope that helps!
Looking at the sentence, it's is obvious that 'Amazon' is the adjective word that describes the birds in South America. Other than that, it is being capitalized because it is at the same time a nationality / race.
It symbolizes him looking across looking at her dock.