. It creates a single image, the eseence of the fog.
Explanation:
Modernist poetry is impressionistic instead of lyrical, and often focuses on one single image or a vignette to convey its theme and the poem consists of short impressions.
This poem has a lot of character, uses free verse with the normal every day diction of speech but with pointed and sharp small lines to convey the essence of the fog contained in a small space.
The small lines, the impassioned tone without flowery diction is all symbolic of a modernist tinge to the poetry.