This means that the characters, dialogue, setting and plot hold up a mirror to the human experience. When we see a play, we see ourselves and our actions, our thoughts, our motivations. Things said and done in a play might not be done in real life, but if they are acted out in a play, then those words and actions show us how we are human, fallible, ignorant, limited. Some plays show us how we can overcome these limitations; some plays are more jaded and cynical. But, all plays mirror humanity — the good, the bad and the ugly.

Hope this helps. Cheers, K

Miller is saying there is a secret to writing a story or creating a play/movie that will catch a person’s attention. That secret lies within a person’s ability to show something in real life (which everyone should be able to identify with) from an “outside looking in” perspective and point out how the people involved only see what they want to see while ignoring the “big picture.” We as the viewers or readers see the obvious folly of the characters, but when we see them in a situation we can identify with, it makes it that much more funny or tragic because we see ourselves making the same mistakes or drawing the same incorrect conclusions.