While this was during the moody teenage years, another reason for the grim face might be trying to use iso 32 film indoors in available light. It probably needed 1/2 second exposure or longer.
Although I'm holding a cable release it looks like the self-timer was used for this photo (it's between the motor drive grip and the lens).
I loved that super-heavyweight Samson tripod, a loaner from my dad. I think it was intended for large video cameras.
Olympus OM-1n, Zuiko 100/2.8, Panatomic-X.