Human ingenuity can be, well, ingenious. Witness the Napoleon cane, circa 1815 CE. This was made when the former Emperor was in, I think, his second exile, to St. Helena.
It was considered treasonous in certain circles to be a supporter of old Bony Part at the time, and you best not have his portrait hanging on your drawing room wall, else you find yourself in deep merde.
So, some clever fellow came up with the notion of the cane handle. This was done in such a manner that at first glance, the handle appeared to be nothing but a bit of ivory carved in an innocuous design, like something turned on a lathe. However, hold it in front of a strong light source, and the shadow produced was a silhouette of His Former Excellency Himself.
Passing clever, these hairless great apes, non?