Or it could be... (Destiny)

by Dagoonite, Somewhere in Iowa, lost in a cornfield., Saturday, March 14, 2015, 03:02 (3338 days ago) @ Cody Miller

It very well could be a reference to the movie The Dark Mirror. It's an evil twin movie, in essence. Kind of. It does some almost-interesting things with the premise that have, unfortunately, been done to death in media since then. Kind of like how Airplane! seems lame to some people who see it for the first time since everybody else has ripped it off.

(To be honest, the only reason why I remember it is because of Olivia de Havilland.)

I always thought that's what it meant; an equal but opposite.