There are several reasons why Carroll might frame his story this way. One is formal: it fits with many of the themes in the story, such as mistaking appearance for reality, words for physical reality, and so on. This is one more occasion of mirroring/doubling in the work.
Another major reason is psychological. Any apparent social critiques in the work can be dismissed as wisps of a dream. It is a way to say difficult or painful things and taking the sting away, like saying, "Just kidding!"
See eNotes Ad-Free
Start your 48-hour free trial to get access to more than 30,000 additional guides and more than 350,000 Homework Help questions answered by our experts.
Already a member? Log in here.