What effect does ezra pound achieve by excluding the phrase "are like" in favor of a semicolon in this poem, turning the lines into a metaphor instead of a simile?

in a station of the metro
the apparition of these faces in the crowd;
petals on a wet, black bough.

it reflects the imagist ideal of capturing as many impressions of a subject as possible.
it reflects the imagist ideal of contrasting ideas by using detailed descriptions.
it reflects the imagist ideal of separate images that overlap to present one clear idea.
it reflects the imagist ideal of imitating impressionism and blurring images.
it reflects the imagist ideal of joining separate ideas with a semicolon instead of a comma.