How about this from Merriam Webster
Mise en abyme
- placement at the center of an escutcheon of a smaller copy of the same escutcheon
- containment of an entity within another identical entity
- image of an image
And from Wikipedia, how mise en abyme is used in film:
Mise-en-abîme occurs within a text when there is a reduplication of images or concepts referring to the textual whole.[...] In film, the meaning of "mise en abyme" is similar to the artistic definition, but also includes the idea of a "dream within a dream". For example, a character awakens from a dream and later discovers that s/he is still dreaming.
The article on Wikipedia specifically mentions Inception as an example of this.
