Why the Masque? (Black and White)

Why is he wearing the mask? Is he going to a costume party? Or is he getting ready slaughter a bunch of annoying teenagers (played by actors in their mid to late twenties)? Or does he plan to do some welding and he likes to personalize his tools? Perhaps he doesn’t like his face? Or perhaps he knows that others don’t like it so he keeps it hidden out of politeness?

What’s the story here?