I was talking about the Nintendo store in NYC. But what Legend said, yes. It was hard to grasp as a demo station at least. I saw more people having similar problems. Also they said press L+R, which I did and nothing happened. It was only when I figured out there were small buttons on top of each half a controller by myself that I could start Mario for exampleRight of you've only got a single joycon then the controls are rotated as you hold it sideways. You press L and R at the same time to let the system know what you're using as a controller.
I'm surprised they'd have a demo set up with only one joycon though.