Originally Posted by jeeter
In the computer world, that is called a "bang light" or "attention indicator". It generally doesn't point a particulat problem but is designed to warn you that something is wrong. You then have to research further to find what is exactly the issue. This is also the case with BMWs. It just tells you that there is something that it is not happy about. In this case, you didn't have your seat belt fastened.
or just a heavy item resting on the passenger seat
perhaps a blonde