“To point at the moon a finger is needed, but woe to those who take the finger for the moon.” – D.T. Suzuki
This is the second time in as many days you’ve come to us with problem involving your English studies, which tells me it’s probably time for you to back up and refactor your analysis of what is being asked.
There are two entirely separate problems here, which you have mistaken for there being a single problem. They are as follows:
(1) What am I being asked to do, and why?
and
(2) What is the significance of this sonnet?
Your teacher, whoever he or she is, is concerned solely with your response to #1. However, it’s important for you to realize that most people who teach English got there as a result of their obsession with #2. They therefore, unintentionally, destroy any interest you might have had in #2 in your effort to deal with #1. They will train you very well in how to regurgitate a series of words without any real understanding of what it is that you’re writing. They will mistake this for understanding because they are stupid, and because they have failed to understand that the real purpose of school is teaching you to conform through the rote regurgitation of information on command.
So, the first thing you need to do before you can answer this question (or any other posed to you in school) is whether in fact you have any interest in #2. Because if you do, it will make it harder to deal with #1. If your only interest is in satisfying the demands of your assignment, don’t worry about the sonnet. Find a few essays on sonnets, get a feel for the wording, and regurgitate it at your teacher. Make sure to use the specific words and phrases your teacher uses in your answer, because that’s what he or she is looking for.
On the other hand, if you actually have any interest in understanding the sonnet (or any other part of English literature), I implore you to forget everything they’re teaching you in school. Their ruthless vivisection of prose and poetry does more to make people hate language than anything this side of Fox News. How does this poem make you feel? Don’t let anyone tell you what is “classic” and what is not. This poem, for example, strikes me as being trite and sentimentalist. I’m more of a Percy Shelley or Dorothy Parker man; I like my poetry with a thick slather of bitter, curdled disappointment and cynicism. You do not need to like this particular poem, and if you don’t, feel free to simply reflect back your teacher’s expectations without worrying about whether or not you’ve grokked the poet.
But please, regardless of how you decide to answer, do your own explorations and find out what sort of prose and verse you like. Then keep it safely hidden inside your head, where they can’t flay off its skin in dabble their thick sausage fingers in its innards.