Brevity can sometimes be the worst enemy of clarity.
I was in France recently and came across a lot of symbol based messages, some such as this one causing a bit of confusion and a few smirks. Ideally symbol signs or pictograms overcome the familar problems that translation create, but some of them just don't quite manage to cross the cultural divide.
At first, with this one, you think the "line through" symbol indicating NO seems to have been left out of all the banned things apart from the smoking. But then you realise the blue icon means you have to take a shower before entering the pool, so all the red ones are the banned things, which means there's a double negative on the smoking issue. Smoking is compulsory. Not surprising in France, really!
Is a cocktail glass enough to indicate a ban on alcohol? The olive is hilarious! And yet it's quite a serious issue. Why would you not want someone wearing a football jersey to use the pool? Is that class discrimination or something? Or just a joke? The internal logic suggests that either you are not allowed to use flippers or shoes in the pool, or you are not permitted to wear either boots or flippers around the pool area. It is deemed necessary to say no pushing, so are you allowed jump and dive and splash? You're NOT allowed to wear shorts? Huh! What about a bikini? (Honestly, I think the idea is that men should wear figure-hugging togs rather than loose shorts. The French seem to go for that up-front look and expose as much as possible of their bodies in public during the summer.)
You just have to do your best with these communications, of course, taking them in good faith, but if they had to be used in evidence in a court I'd say a good lawyer would have a lot of fun tearing them to shreds as rules!