Connie Y. answered 08/27/19
BA/MFA in English Lit, Comp & Writing
Perhaps if you look at it this way, you can better understand it: symbolism can be viewed a subset of imagism. Any symbol has meaning (a commonly shared one) separate from itself, e.g. math symbols and even religious symbols, but imagism is a way to create pictures in the mind. Metaphors and similes fall into the "image" category. Drawing on the five senses is the best way to create images in the reader's mind with sight and sound being the easiest and most used, but smell, taste, and touch being the best because of the personal emotional connection--if done well, that is.