CIRCUITPY
That would be the name of the virtual USB disk CircuitPython creates when running on a Raspberry Pi Pico and connected to a desktop Pi.
So has the Pico rebooted itself and provoked the pop-up?
It makes sense to use a Pico running CircuitPython to interface to buttons and sensors the exhibit may be using. I find dozens of these pop-ups appearing on my Pi desktop when I return to it after doing remote code development with my Pico.