It's a parking light. They're normally operated by the turn-signal switch on the steering column. If you used the turn-signal to indicate you're going to park and subsequently forgot to turn it off, the parking light at that side of the car will turn on as soon as you switch off the ignition. I think that is also how it went in that case.
The blue light's probably a reflection of white/yellow lights bouncing off the phantom's xenon/HID lights (look at the ball-ish shape). Xenon/HID lights are blue-ish colored.
Example is our BMW's xenon reflecting white light as blue light.
Lol. Blue light on a RR phantom can arouse so much interest! xP
That's ice which it's parked on. Looks kinda wicked, M3 with winter tyres. That miserable phone pic cannot do real justice to it, but that had really, really nice rims. Those aren't the standard ones. They had BMW M-badges on them so they could be somekind of option.