The setting actually turns on just one side of the car’s parking lights. It was accidentally engaged when the car was dropped off at my house. I thought the car was malfunctioning because the right light stayed on after I locked it…for a long time.
This feature is common in Europe but rarely seen in the U.S., even on European cars imported here. The reasoning is, when you park on a street in Europe you only want to turn on the parking lights on the side facing the street. We assume this is to keep from annoying the folks living on the other side of the sidewalk.