Why do European books have the words on the spine the opposite way around?

I’ve never noticed it being European or from anywhere else. To me, it seems quite rare. In fact, just looking at the covers of the books on my bookshelf, the only book like that that I have was published by the US government.

Side question: why do American coins have the image on the two sides upside-down in relation to each other? I don’t think I’ve seen that anywhere else.