Why we chose this

Vella pulled a smooth rock out of a lake in 1991, lost it, found it in her car six months later and threw a party for its return. These are not that rock. They are not rocks at all, which is Magritte's position and Magritte's title, with the hovering boulder taken from The Castle of the Pyrenees. The pieces are also quines, software that prints its own source, so the question of what a thing is gets asked twice.