But on a day-to-day level, one of the sub-sets of semiotics is the appropriateness of pictorial signs within the society that they are used.
A "Gents toilet" sign that shows a human wearing trousers would give the wrong semiotic signal to a society where women wore trousers, for instance.

The English road sign for "Men at Work" is someone sticking a shovel into a pile of rubble - it has been translated by strangers to our culture as, "Man opening an umbrella!"