Really cool that you can actually see the IR emitters in the Wii bar as the mobile camera can detect some of this light and shows it as some kind of purple.
Unnecessary rant
The other day I saw a video explaining how the Wii remote knows where you are pointing to by using the difference in time between both lights from the bar so you can use two candles instead of the bar if you lose it, giving your Wii setup a more witchy look.
It’s not the difference in time. It has an IR camera that will basically see two bright dots on a black background. That lets some relatively simple math get you rotation and distance from the bar using the distance between the dots, and pointing position from the absolute position of the dots in the camera’s frame.
The candles thing does work - I’ve tried it before. There are also 3rd party sensor bars you can buy.