From the perspective of context, the first is the layering of the picture, which makes readers enter the situation with the author's description, while the repeated description of homesickness sets off the author's sigh that he is homesick and can't go home.
From the rhetorical point of view, it needs to be scrutinized repeatedly, and it is also the connection between sections and sections of poetry.
I don't know if my opinion on this point satisfies you.