Here’s what I think these international signs really mean.
Walk jauntily down the stairs while wearing a hat. Don’t use your best posture. Or maybe you should dance. Not totally sure on this one.
Use more of your bad posture. And don’t forget your hat. Stay in the lines.
Push over green bikes if they are in your way. Or wear a bike on your head while walking a child who is dancing. Again, that hat is important.
I particularly like this one on the trams. Don’t create clouds, keep your pockets in your pants, no jamming, no sawing, and if you have your feet up, have both of them on the back of the seat (or is it have both of them on the seat?). The words say that they prefer not to plaster these all over the whole tram. Once should be sufficient.