Struggling to understand and how to write in the postmodern way [View all]

Are authors using the concept more inside the characters' heads, more sarcastic and satirical, sort of an exaggerated surreal setting and action? I've asked 2 AI's to weigh in but it's not making sense to me. They say you extract from the text, make the reader aware it's a story. I can't see how that's any benefit.