That makes sense if the amp is pointed away. I went back and watched again. I saw the one guy shaking the other. Are they a team that causes a commotion so that people look at them and not at the person behind them who is lifting their wallet?
I saw one lady who was wearing her backpack in the front and wondered about that. I guess it's fairly common.

Thanks for the well-wishes on the name. Some people are calling me Blondie. ;)