No Crossing No Leaning

One of my closest friends came back from her five-day business trip to China. Knowing I'm a very big fan of public signs especially from other countries, she kindly sent me some photos of public signs she had taken during the trip. This is the one she captured, as she told me, in the city called Zhengzhou.

This is the very first time for me to see a sign whose main language is Chinese (we have a lot of signs written both in Japanese and Chinese here in Japan). I've never learned Chinese, but I can see what the communicative purpose is thanks to the English translations and pictures on the sign. However the wording "No Crossing" looks a bit odd I guess? It seems to be saying that you must not sit astride the balustrade because it is dangerous.