How does Robin McKinley use imagery in The Blue Sword?

Examples of Imagery:

"There seemed a roaring in the air that beat on her eardrums and pressed against her eyeballs till she blinked. Then he looked up abruptly, as if from some unfathomable depth of thought, and saw her; their eyes met. The man's eyes were yellow as gold, the hot liquid in a smelter's furnace."

"She raised her eyes to where his should be, under his blazing white helm, and saw spots of red fire; below that, teeth were bared in a grin in a jaw that might once have been human. The power that washed over that face, that rolled down the arms and into the sword and shield, was that of demonkind, and Harry knew she was no match for this one, and in spite of the heat of Gonturan in her hand, her heart was cold with fear."