For me, it may be that the toilet paper roll needs to have the open end away from the wall. I don't want to reach under the roll to take a piece! That's ludicrous!
That or my recent addiction to correcting people when they use "less" when they should use "fewer"
No, design and design language are two different things. A design language is a set of design rules that define a common look and feel across a product line. There’s usually a manual put together by a designer and their team defining what these commonalities are.
Look up “Apple Snow White design language“ for example.