Public Toilet Technology - How do you turn the taps on?

I've travelled far and wide, stayed in the finest of hotels, used the basics of bathrooms.

I've found the foot pedals, operated the sensors, turned dials, twisted taps, sussed out if the tap turns left or right or if the hot and cold is on the left or the right.

But this one stumped me and I had to ask at reception how to turn the tap on. Apparently, you lift the elbow and turn left or right to adjust the water temperature.

What's the weirdest tap you've come across?

I'm not the only one who has this issue, see what Michael McIntyre had to say on the subject.