About a year later, a threaded hole was added at the right-hand front above the flashbulb synchronising contacts for securing the flashgun to the camera (version 4).
I would switch off the lights, open the camera's shutter, and then walk around the darkroom illuminating the scene with multiple bursts from a handheld flashgun.
We call that strobist's kit, consisting of small flashguns, light stands and umbrellas or diffusers; not the heavy lighting equipment you see in studios.