Frost takes an activity (apple-picking) that most would consider either good clean fun or hard manual labor, and gives it an unfamiliar and oh-so-slightly disconcerting edge. Apple-picking is done every year at orchards, and it signals the end of the harvesting season and the beginning of winter. It is a long process that cannot be done in a day or two at a large orchard. But this poem follows the poet Ezra Pound's famous advice: "Make it new." Its perspective of tradition and customs is analogous to the perspective of the speaker of the poem when he looks through that sheet of ice. The disorientation of the experience stays with you long afterwards.
Frost treats apple-picking as a secular ritual, parallel to the rituals of Christianity.
The speaker of this poem is a gentleman-farmer, the Jeffersonian ideal of a true democratic citizen.