So far I have pulled several aspects of symbolism, when I think about the representations of a society within a fantasy realm. I think the methods of symbolism are incredibly relevant to fantasy, not only because some symbolist work has fantastical pursuits, but also because of the suggestive nature of symbolist work. I strongly believe that in order to be invested in the fantasy genre, it requires some degree of imagination and creativity, suggestive imagery is the catalyst for provoking inner narratives and would be a very important aspect to fueling the imagination.
So this aspect of visual theory might be applicable to the drawings which characterize representations. Seurat, a famous symbolist artist (although he would not like to be classified as such) has some good theories on the manipulation of mood. For one, most of his works did an excellent job of using filters, some overarching color pallate which influenced an entire portion of the canvas, even though there would be blues in one section they still maintained a warm and red tone. Another prominant aspect of his work is manipulating the flow in order to communicate sorrow, fear, or perhaps joy and gaiety. The diagrams in the book explain more.