The icicles here almost seem to have a life of their own. They aren't hanging from the wall; they "hang by" it. Forgive us the pun, but they're chillin' like a couple of teenagers.
And Tom bears logs into the hall, (3)
Tom is an example of how people can use nature to survive nature. Wait—what? Tom is using "logs" (nature) to make a nice warm fire so he doesn't die as a result of nature's savage winter.
Then nightly sings the staring owl, "Tu-whit, to-who!"— (7-8)
Okay seriously, this doesn't really sound like an owl at all. Well, it kind of does, but not exactly. Human language cannot adequately describe nature—that seems to be the lesson here.
When all aloud the wind doth blow, (10)
The wind "doth blow," and Dick the shepherd "blows his nail." Maybe man and nature aren't so different after all. They both "blow" on things, after all.
And coughing drowns the parson's saw, And birds sit brooding in the snow, And Marian's nose looks red and raw; (11-13)
The differences between man and nature are quite apparent in this little passage. Marian's nose just can't take the cold, and neither can the lungs of that person whose coughing keeps interrupting the parson. In contrast, some little birds are doing just fine out there in the snow.