The first time I saw it, I honestly thought it was a joke. About three years ago, in my first visit to German houses. I simply laughed about it while peeing as a man is supposed to be, standing up and aim-playing. It took me a while to understand what it meant. What do you think it means? Think for a while. Maybe you do too have the obvious answer popping out of your common sense, just like Germans do. For me it took a while to understand it. So, what is it for? It's a way preventive way to clean the toilet. Men splash more than women, women usually (but not exclusively) do the cleaning. This, is a women-wise cultural innovation. Aparently it started a couple of decades ago. From a citizenship perspective, it's simply great. If you want persons to care more about the wellness of the toilet and the bath floor and the cleaning frequency and the laboriousness implied from it... Make men sit to pee! It's a whole different perspective.
Now, I even discovered that the final drop is quite an issue. Ladies and gentlemen, I'm 32 years old and I'm relearning how to pee.