A light dependent resistor (LDR) on top of the enclosure controls the turning of virtual knobs when used in-conjunction with the available properties of a compatible effect pedal. Whether you're waving your hand or stomping your foot, the amount of light that reaches the LDR can affect the amount of expression.
Offering hardware functionality that increases compatability across the wide range of expression formats, the creative control is in your hands to adjust and refine the interaction.