These two basic thoughts are not mutually exclusive. For example, an action story may be given added heft by incorporating the first kind of reflection into the narrative. This happens in Lethal Weapon when Riggs bares his soul to Murtaugh, admitting that killing people is "the only thing I was ever good at."
Also, notice how this is different from other definitions of the midpoint you'll see. Virtually all books on the craft approach it as another "plot" point. Something external happens that changes the course of the story. But what I detect is a character point, something internal, which has the added benefit of bonding audience and character on a deeper level.
Of course, not every film or book will have a "mirror moment" like I've described. But the ones that do have a depth about them, a better cohesion and focus, and a satisfying arc. That's the sort of thing that makes a reader search out more of an author's work.