The correct answer is Petrarchan (or Italian) sonnet. It is structurally divided into two stanzas, an 8-line stanza (an octave), and a 6-line stanza (sestet). Even the rhyme supports this structural division: the octave usually has the ABBAABBA rhyme pattern, while the rhyme pattern of the sestet may vary (the most typical arrangements being CDECDE or CDCDCD).
These lines taken from "The Snow Man" might be interpreted in these ways. One possibility is to have an objective view of the nature of a winter landscape without attributing any personal emotions to it. The other interpretarion is the assiciation of winter with misery, sadness and loneliness, the feelings that are related to the picture of the wind blowing with just a few leaves.