Very ingenious and time saving as well as water saving. Plus the fact that the loo was located in a separate closet sized room meant that someone else could bathe, wash up or apply make-up at the same time-- a great survival mechanism with three daughters and a wife sharing the facilities.
The more complicated a thing is, the harder it is to clean.
When I was in Britain, the toilets were often in special little rooms separate from the sink, shower or tub. Very practical idea, I thought.