1. The double-mirroring effect created by placing an image within an image and so on, repeating infinitely (infinite regression); 2. A reflexive strategy where the content of a medium is the medium itself: for example, Shakespeare’s Hamlet features a play within a play and Fellini’s 8½ (1963) is a film within a film; 3. A formal technique in Western art of placing a small copy of an image inside a larger one. Chandler, Daniel and Rod Munday. A Dictionary of Media and Communication. 3rd ed. Oxford UP, 2020.