To control the cassette Lamp you can choose between two options.

The (from my point of view) coolest option is to control the brightness and color of the lamp using two rotary encoders that are installed in that way that they can be accessed via a pencil from the outside. 

An example of this is shown here:

The other way to control it is via an APDS-9960 gesture sensor that is installed in the inside of the lamp. This way the lamp can be controlled by specific hand gestures. Sadly this does not work reliable in all lightning conditions.