Emotion Gumball​​​​​​​

Emotion Gumball is a functional gumball machine designed to tell viewers what they are feeling-- or rather, to help them know what they are feeling at the moment. 

All of the white faces have ambiguous emotions to have the viewers project their actual, subconscious emotion into reality. The few yellow faces are the only ones that are unambiguously happy, which makes viewers want to receive them.