Check the video to better understand it - 
https://www.youtube.com/watch?v=gXOOO1Rk1IU

Objective: To save water by 70% at washbasin during hand wash activity.

Synopsis:
A water tap at the washbasin should not be touched and should be operated with the foot.
The user needs to push a lever at the floor that will flow the water flow at the water tap in the wash basin.

It will make better usage of water and brings better hygiene.

Analogy:
Tailor’s sewing machine. The tailor sits on a chair, and then use his feet to manage the mechanics of sewing machine.
Hands are free from managing the mechanics and sewing the cloth becomes much easier. Similarly, now think for making a wash basin where foot is used to control the flow of water, hands are free.