The work is a traffic signal** largely covered in wood varnish*** and then put into outer space. A further, likely integral, aspect of the work has the traffic signal (somehow) turning to at least 50% wood****.
*Being that realization of the work will likely be difficult, a video sketch comes with this certificate as a stand-in. **The traffic signal can be powered or not. ***Any wood varnish will do as long as applied (somewhat) generously. ****Any type of wood would be good (including extraterrestrial varieties).