picture is from a restaurant in Santa Barbara.
There is no urinal in the men's restroom. The fixture
in the corner affords a certain activity.
To try to discourage this activity someone taped a
small sign to the wall above the fixture. The sign
says "This is a mop sink."
mop sink looks enough like a urinal to use it as
one. When simple things have signs, especially homemade
signs, it is usually a signal that they aren't