Literary ambiguity is when there are different meanings so you're uncertain of the meaning. Puns are often the root of ambiguity. This is like Abbott and Costello's "Who's on First" and on p. 32 of The Enormous Egg when Pop says about collecting eggs, "So do we. We collect them twice a day." Pop was trying to be humorous with his punny ambiguous answer.

Imagery creates pictures in the reader's mind through use of adjective and details. In The Lion, the Witch, and the Wardrobe on page 78 CS Lewis gives a clear picture of the beavers' hut and dam.

Oxymorons are two words or thoughts that contradict each other. In The Lion, the Witch, and the Wardrobe Susan and Lucy often say, "Do stop." 

The point of view is the narrator's perspective/relationship to the characters and reader. In first person stories, like the Enormous Egg, one of the story's characters narrates using the pronoun "I". In third person stories, like the Lion, the Witch, and the Wardrobe, the narrator is a person outside the story telling the tale. 

Sarcasm and satire are  literary terms that ridicule or make fun of the vices and follies of mankind. In the Great Brain, Tom says, "I've got to rest my Great Brain for when we have another problem that you grown-ups can't solve." In The Enormous Egg, Pop says, "This is no time to worry about clothes. We always wear our bathrobes when our **(surprise)** hatch."

The setting is the time and place--the where and when a story takes is set aka takes place. The Lion, the Witch, and the Wardrobe is set in two places, Narnia and inside a castle-like mansion in England. The story takes place during World War II in the late 1930s and early 1940s.