A Falling Plate camera uses either paper or glass plate holders that are loaded into the camera. There are twelve paper plates in this camera. So, unless you have a changing bag, you have 12 shots available to you when you take the camera out.
Each plate slides along two tracks and all are kept in place by the pressure spring which is driven by the plate on which it is fixed.
On top of the camera is a slider that allows a plate to release from the stack - note the two slots in the top of the plates. The released plate then falls down into the bottom of the camera body. The cavity for this can be seen just under the pressure plate.