[Thanks to Phil]A pinhole photo in an egg, article.
The egg shell is both the camera and the photo. What an excellent idea.
Now block the opening with a wrought-brass pin-holed plate, trying to restore the natural egg-ness of the shell. With the black tape seal the structure. You’ll notice that the shell is really transparent: to avoid any problem, wrap it with the black cloth, carefully leaving out the pinhole. During each stage of this process the egg could break. Usually it does.
I suspect this will become an art form like that thing with photographing the viewfinder of a medium format camera, only better and more timeless.