Dash lights - anyone noticed this on their A4?

[80sGuy]

Either I'm being paranoid or the car's behaving erratically, I noticed this after I start the car in my carport garage and the usual 'reds' lid up from the dash (meters, on board computer, etc.) except for both the speedometer and the rpm dials, which remained pitched black and/or unless I turned the headlights on. It goes off if I turned the lights off, but.......as soon as I put it in gear and roll out of the garage, the rest of the round dials lights up (the regular bright white lit numeric portions).
The funny thing is this; as soon as I entered the dark garage, once again, the dials shuts off. The only things remaining lit are the red objects (meters, on board, mileages, etc.). Seems like it is controlled by a sensor.

I've never paid any attention to this until now. It doesn't look like a defect but it is somewhat weird and to be honest, it's kind of cool. Why do the dials light up only when I'm entering sunlight and what is the purpose of this design? Is the feature designed for when the car's in motion only and knows when to stay lit in case if I'm driving through a dark tunnel in the middle of a sunny afternoon?

Not sure if you guys noticed it, but please check yours out and help me confirm that this is indeed normal.

[muffinman]

The dash lights do that to "remind" you to turn on your headlights when it gets dim outside. So, the cluster is lit during daylight and dims when it's dark so that you're forced to turn your headlights on.

Of course, this only applies for people who have to manually turn their headlights off/on

[vtracer20]

when i have my lights off only the reg needle lights up...but i dont notice it as much during day light, i think there mihgt be a light sensor