It's for their winter "Ice" tire and the silver A4 is scooting up and down snow covered hills.
I noticed in the small print something to the effect that the vehicle has all wheel drive. Go Quattro!

It was cool. I think the visual would immediately make sense to Audi owners (especially those with Quattro) what they're trying to get across: Quattro+snow tires=Newest winter sport since snowboarding!