How does Ezra Pound use imagery in The River Merchant's Wife: A Letter?

In a 1918 essay titled "Chinese Poetry," Pound described the central qualities of the Chinese verse-form. One was the use of nature imagery to explain or indicate human emotion or set mood. He referred to this as "metaphor by sympathy." This use of nature is a major factor in setting the tone of the final stanzas of "The River-Merchant's Wife: A Letter." While the five months the husband has been gone may not seem a terrible burden to the reader initially, Pound uses nature to cue the reader to mood. The "sorrowful" monkeys mirror the wife's feelings. The fact that the merchant "dragged [his] feet," cutting a path through the moss, shows his reluctance to leave; the fact that the moss has eradicated those marks of his presence, casts a worrying shadow. Much of nature, the wind, the seasons, the leaves, seems out of order reinforcing the wife's foreboding. "The paired butterflies" provide a final, almost unbearable, touch. While these delicate creatures remain together, they torment her with the reminder that her own love is gone.