Its emphasises the writers message and keeps it constant, andstuck in the readers mind, so therefore the reader will want to read on due to the fact that they'd want to find out more about what is actually happening and it gets them hooked.
Emily Dickinson is world renown among poets and those who love literature for her emphasis on both thought and feeling.
She is considered a master of form and syntax and is often called 'a poet of paradox'.
Generally speaking her poems tend to be short and they usually use only one voice (which is not necessarily that of the poet). She published well over 1800 poems of which only a handful of them were titled as is the case of the poem listed here.
Notice her use of form and paradox in referring to hope as a thing with feathers, something that never asks for anything in return.
Expository essays should be FAIR to other points of view.