18th Century Toilets Could Be Camouflaged as Books
People throughout history have occasionally needed to conceal items that they didn't want others to see, much as how Disney hides less-than-magical structures. Not out of any sense of security, but rather out of politeness. That is how we came to have toilets that blend in.
The bathroom is still considered private even today, and for good reason. Probably, you don't want to see anyone utilizing it. But in the 18th century, some people found it overwhelming just to be aware of its existence. That is how things like a toilet disguised as a massive book come forth. Some of these appear to have been ostentatious decorative flourishes, but it has also been theorized that some of them might have been ingenious strategies for concealing a chamber pot while traveling. This would have been regarded as a lowbrow joke both then and now, since some people have always found toilet humor to be amusing.