Wiktionary
n. (context literary theory English) self-reflection or introspection in a literary or other artistic work; the representation of the whole work embedded in a work.
Wikipedia
Mise en abyme (; also mise en abîme) is a French term derived from heraldry, and literally means "placed into abyss". The term has developed a number of particular senses in modern criticism since it was picked up from heraldry by the French author André Gide.
A common sense of the phrase is the visual experience of standing between two mirrors, then seeing as a result an infinite reproduction of one's image. Another is the Droste effect, in which a picture appears within itself, in a place where a similar picture would realistically be expected to appear. That is named after the 1904 Droste cocoa package, which depicts a woman holding a tray bearing a Droste cocoa package, which bears a smaller version of her image. The phrase has several other meanings, however, in the realms of the creative arts and literary theory. In Western art history, "mise en abyme" is a formal technique in which an image contains a smaller copy of itself, in a sequence appearing to recur infinitely; "recursive" is another term for this.