It’s the unusual beauty of the woods that bewitches the poet. While on his way, he halts to appreciate the serene magnificence of the woods and revel in its soothing silence.
The first sight that captures the poet’s attention is the pristine beauty of the woods covered in snow. The expression “woods fill up with snow” implies that not only the ground but even the trees, their branches and leaves, are blanketed with snow.
The absence of people and objects in the scene too does significantly contribute to the poet’s visual experience in the woods. The owner of the woods, whom the poet probably knows, isn’t around nor is there any farmhouse in the woods. In their absence, the quiet woods to the poet appear all the more appealing as a place unaffected by human activities. Besides, the view of the frozen lake is another sight that attracts the poet’s attention. It underscores the point that it is freezing cold.
The ecstatic silence of the woods is the poet’s most important experience with regard to his experience of sound. It is this all-pervading silence that makes the other sound experiences so prominently felt by the poet. The first being the tinkle of the harness bell tied to the horse’s neck which rings aloud in the uninhabited place. Secondly, it’s the soft continuous sound made by the blowing of gentle breeze and the falling of smooth and fleecy snowflakes.
All these experiences of sights and sounds hypnotize the poet in a way that he is reluctant to leave the woods.
Before answering your question, I want to highly recommend reading this poem out loud to yourself. It's a wonderful sounding poem. The rhyme is just awesome. Okay enough mushy poetry stuff.
Sights of the poem: The speaker is riding his horse at night. The second stanza indicates that it is a very dark evening.
"The darkest evening of the year."
Snow is falling, so the likely time of year is the dead of winter. The speaker announces in the first stanza that he has stopped beside a wooded forest area. On his other side is a lake. Even though the poem mentions a house, a village, and a farmhouse, the horse and rider are not near any kind of human habitation.
"My little horse must think it queerTo stop without a farmhouse near"
"The only other sound’s the sweepOf easy wind and downy flake."