Make Your Character's Problems Look Deeper By Having Them Punch A Mirror
Your movie has begun and things are occurring, but now you need to convey how much these events have created inner turmoil for your main character. Unfortunately, you've been told that having them say, "Goodness, I sure have a troubled inner life!" out loud isn't a good option. How should they deal with the complicated issues weighing them down? Well, according to movies, they should punch the hell out of themselves in a mirror. You know, like adults.
When V from V For Vendetta is upset that Evey doesn't reciprocate his love for her (year-long torture sessions will do that sometimes), he apparently blames his Freddy-Krueger-esque skin condition for it, because he takes all his anger out on an unsuspecting mirror.
It's those bangs, dude. You're not Zooey Deschanel. (We think?)
And how distraught is Tony Stark that his weapons are being used by terrorists in the first Iron Man? Triple-distraught, because when he sees his own reflection, he shoots down three glass windows.
What truly cranks the profundity up to 11, though, is whenever a character looks at themselves in the shattered glass. Naturally, their reflection is all sorts of screwed up, because, like, so is their soul. Right before Brandon Lee assumes his avenging vigilante identity in The Crow, he smashes his mirror ... and probably feels rather dumb right away, because he's gonna need it to put on his Juggalo makeup.
Sometimes they don't even have to hit the mirror to break it. In Carrie (2013), Carrie is struggling with the realization that she's clearly Carrie from the movie Carrie (1976), so she telekinetically breaks a mirror and looks at her messed-up reflection -- just like the other Carrie did. John Travolta does something similar in Phenomenon.