How does C. S. Lewis use imagery in The Last Battle?

Imagery:

“...... the great waterfall pours down into it with a noise like everlasting thunder, and the River of Narnia flows out on the other side. The waterfall keeps the Pool always dancing and bubbling and churning round and round as if it were on the boil”.

“.... he was between twenty and twenty-five years old, his shoulders were already broad and strong and his limbs full of hard muscle, but his beard was still scanty. He had blue eyes and a fearless, honest face”.

“.... you know how sad your dog’s face can look sometimes, think of that and then think of all the faces of those Beasts – all those honest, humble, bewildered Beasts – all far sadder than that. Every tail was down, every whisker drooped. It would have broken your heart with very pity to see their faces”.