How does Lloyd Alexander use imagery in Taran Wanderer?

Examples of Imagery:

"It was full springtime, with promise of the richest summer the farm had ever seen. The orchard was white with fragrant blossoms; the newly planted fields lay light as green mist. Yet the sights and scents gave Taran little joy. To him, Caer Dallben was empty." Chapter 1, Who am I?, p. 15

"Taran rode slowly, head high, with all the assurance he could muster. But once out of sight of the stronghold, the companions clapped heels into their horses' flanks and galloped for dear life." Chapter 3, Goryon and Gast, p. 53

"Heart bursting in his chest, Taran doubled his pace; though before he could set foot in the rapids, he saw the King's red beard sink below the churning water, and cried out in despair as Smoit disappeared over the brink." Chapter 4, A Matter of Cows, p. 72