Apparently it's a thing in Germany that dudes are supposed to sit when they use the toilet, for all activities that one would do on a toilet. As far as I know for how things are done in the US (without being a dude myself), I understand that American dudes (tend to) stand up when they are urinating.
Take this as a warning, American guys: the Ampelmann wants YOU to sit down at all times when using the toilet. I saw this jaunty little sign in the (unisex) bathroom of a thrift store in Kaiserslautern.
(I am also super curious about the images. Did someone hijack some Ampelmann images and Photoshop them or are there official images like this?)