Signs in Japan are nothing short of spectacular. Sometimes spectacularly bad. I think a good sign communicates an unambiguous message. The truly awful ones in Japan, and there are an impressive number and variety of them, all leave much room for interpretation. Here are two of the truly great signs followed by the most spectacularly awful sign I may have ever seen.
In case you have difficulty reading the sign as an image, here's the text:
Please do not see it while drinking drink. The PET bottle caps it and put it in a bag, and please carry it. Please see the thing which the chief does not have after finishing drinking.
And here is the sign in context, on a vending machine near a rest area on the grounds of Nijo castle in Kyoto.
And, just in case you come away thinking that only the dog-related signs in Japan are clear, here's one to dispel that notion:
To me, it looks like a dog giving a pair of cats a lecture about garbage, but really, your guess is as good as mine!