The sentences in this excerpt from John Barth's "Lost in the Funhouse" that show the postmodern element of self-reflexivity are:
3)Initials, blanks, or both were often substituted for proper names in nineteenth century fiction to enhance the illusion of reality.
4)Interestingly, as with other aspects of realism, it is an illusion that is being enhanced, by purely artificial means.
Self-reflexivity is a literary device that consists in making the author's manner of composition the main focus of attention. While the writer tells a story, he/she also tells the readers about the choices made and the organization and structure of the text. This literary device allows the readers to be inside the writer's mind; however, sometimes the writer does not always tell the truth. In that way, it is necessary for the reader to be able to distinguish what is real from what is not. In this two sentences from "Lost in the Funhouse", John Barth refers to literary strategies and choices.