I found these pictures on my camera. I don't know who took them. I don't know the scoop. I do know in this place if you leave anything lying around, it will be picked up and used, thrown away or lost. My guess is that the photographer who is likely 16 and Chinese, but shall remain nameless said to his subjects, "Show me your muscle."
Duuuude, that's your underarm!
What did you want us to do again? (through gritted teeth)