If you find yourself in a lift on your own, particularly one that is mirrored at one end, what do you get up to in the few seconds of total privacy that you have beofre you arrive at your destination? Admire yourself, dance, sing, pick spots?
you practice 'looks' in it? Oh no, I always think there's a secret CCTV camera in it somewhere and some oik will be in an office/cubbyhole somewhere laughing if I did that.
my flatmate likes to play russian roulette, and press the button for the very top floor as well, knowing that when he gets out the lift, someone could be waiting and will have to go all the way up before they can go down.
If there's a mirror then I'll always check myself out. Better still, if there's a security camera then I wave at them, then dance like I'm an extra in Madonna's 'Vogue' video.
I came into the office one weekend and used the elevator and started singing a 70's song at the top of my voice whilst disco dancing. I checked on Monday with a security guard to ask if they had any hidden cameras in there. Thankfully they didn't!