A Day In The Life of Walter MItty
Using daydreams as part of the text structure shows that Walter MItty feels trapped, is treated with great disrespect, and he cannot stand up for himself.
The first characterization of Walter Mitty that is shown is that he feels trapped.
He is always getting challenged by his wife, so to let some steam off, "he raced the engine a little." One of the reasons Mitty has all these daydreams is that he needs an escape from his bossy wife.
Secondly, Walter Mitty is not always treated the best by other people or even Mrs. Mitty.
"A man had had to come out in a wrecking car and unwind them, a young, grinning garageman." As a result, Mitty wore a sling on his right arm as an excuse so the men working at the garage will not disrespect him.
Lastly, Walter Mitty faces a little challenge which is standing up to someone and in this case, his wife.
Eventually he is able to speak up and share how he really feels by saying, "Does it ever occur to you that I am sometimes thinking?" Mitty finally gets the nerves to man up and he does the right thing by speaking his mind to Mrs. Mitty.