It's the Buddy's equivalent of an appendix. It's always been there but no one knows what it's used for.
Seriously, I think it's used in some countries as a day time running light when the headlight isn't turned on.
The Stella has one, too. I think of it as a reminder that your ignition is switched on while the engine is off. It has certainly helped stop me from killing my battery while working in the garage (when I am apt to just leave the key in the ignition).
I wonder if its a "City" light. I know in Japan cars have an extra set of headlights that are low intensity just for driving in the city. Everything is already lit so no need for headlights. Maybe that is just a left over like the deadlights.