How does the author use imagery in the novel, The Harrowing of Gwynedd?

One unusual feature of the author's style is the attention she gives to visual image-building. In the novels which feature warfare, the descriptions of feudal panoply—the bright banners and glittering horses' harness and the warriors' colorful regalia—are painted in vivid and evocative detail. In the present book, passages about the invocation of powerful magic play a climatic part similar to that of battles in standard fantasy. These scenes of magical rites are described step by step so that the reader can visualize and almost feel the objects handled and the unseen powers that are being manipulated. This technique works effectively to strengthen suspense, so that the revelations which end such scenes have maximum impact.