lens !
This is the experience that I bring to my costumers during the markets: urban sketches, mixed compositions, and the speciality of the house: spherical perspective drawings.
The artefact on the computer uses body tracking to follow the movement of your hand.
Here is an article explaining better if you are curious: https://lufo.art/2018/12/vr-art-based-on-handmade-drawings-and-their-innovation/