Based on Lewis Carroll's Alice in Wonderland stories, the film finds Mickey stepping through a looking glass into an alternate Wonderland-style world of anthropomorphic objects.
Animators Frank Thomas and Ollie Johnston used their work on the film as an example of how to bring personality to objects: "There is much more charm and conviction in a character if the eyes and mouth can grow out of the natural appearance, such as the telephone in Thru the Mirror" which answers its own ring and talks to itself.
