What's the difference between symbolism poetry and imagism?

The difference is that symbolism uses more sound images; Imagism uses more visual images (of course, Will also used visual images, and this division is relative).

In the subway station

The appearance of these faces in the crowd;

Petals on wet black branches.

These faces flashed in the crowd like a mirage;

Count the petals on the wet black branches.

In the subway station, there are only two lines of 14, which is an elephant poem. It was written by Pound according to his impression of the subway station in Place de la Concorde in Paris. Although this poem is very short, it took the poet quite a long time to brew and deliberate before he finally put pen to paper.

Beautiful faces flashed in front of Pound in the subway station. On the way home, these faces appeared in front of him again and again, until finally they gradually turned into colorful printed backgrounds. At this time, he had an idea to make a non-realistic painting that purely expressed the spots of color, but he couldn't draw, so he could only use poetry instead. These two lines of poetry are interdependent. Evaluation is an illusion, a ghost. It reminds people of the faces of passengers coming and going. The petals in the second row convey a beautiful message. This kind of message is highlighted by the contrast of dark and wet branches, and it also gives people a vague and overlapping feeling, which makes the artistic conception more full.

This poem is very similar to19th century French impressionism. If you read it repeatedly, the reader can draw a colorful picture. At the same time, they will find this poem very clever in sound processing. The [p] sound in the first line echoes the [p] sound in the second line, but one of them only constitutes an unstressed syllable. There is an [[〔au〕] sound at the end of both lines, but the former has a consonant [d] and the latter does not. The repetition of the second line [e] enhances the musical sense of this short poem. The petals hanging on the wet black branches are used to describe the face that flashed before his eyes, which embodies the poet's convincing imagination.