The people inside the house are mindless drones bleating slogans along the lines of "four legs good, two legs better" just like the good little sheep they are.
These signs are everywhere near me. The good thing though, is they are announcing who they are and I don’t have to waste time going through the process of finding out. They are very helpful.
It is the equivalent of a religious person putting up a sign of the Ten Commandments or going to Sunday School just to hear chatter about people's social lives or attending a social club church on Sunday morning.
People who put up these signs are seeking their god's (little "g" on purpose) approval. They want a check by their name...they want a gold star for attendance.