Nothing wrong with it.
Early morning or when the glare is high, and therefore visibility reduced, they turn on. Helps other people to see your car, not for you to see.
The other feature is called 'autobahn mode'. Above 85mph I think. If you stay above that speed for a certain number of seconds they'll come on. Then if you drop below a certain speed (30 or something) for a certain amount of time, they go off.
And finally, when the wipers are on full monsoon mode, the lights come on (again because visibility is reduced).
No dodgy sensors. Clever engineering.