Here’s what Steiner has to say about it:
Testing a new addition to my Artemis instrument… added a keyboard to be used by the left hand while controlling the pulley with the right. The keyboard of course can also be used with both hands and has a vibrato rod easy for the thumb to use for vibrato. It changes pitch (or other aspects) related to motion, not by position, so it goes right back into tune when not being touched.
This is also a test of CV/voltage control of high powered LED lighting and the new note reference strip on the Artemis.