Know the lights you see at clubs and at theaters? The ones that instantly redirect light by directing it through a quickly rotating mirror? The motorcycle-first adaptive headlight on the BMW K1600GT and BMW K1600GTL works like that. It can compensate for lean angle and pitch to provide ideal illumination at all times. Here's how it works.
As standard on both bikes, a centrally-mounted movable xenon projection light shines up onto a diagonally-mounted mirror, illuminating the road ahead. As the nose of the bike pitches up and down with acceleration or braking, the projector light rotates in its housing to keep the beam level. This can compensate for loads too, so if your pillion passenger is exceptionally fat or you carry bricks in the panniers, the headlight will illuminate the road, not the sky. Basically the rotating light always keeps the beam level.
Things get more interesting if you check the "Adaptive Headlight" box (no word on cost). That adds a stepper motor which turns the mirror on an axis to compensate for lean angle. That also works in conjunction with the pitch compensation to ensure the bike's dynamic movement on the road doesn't affect the throw of the headlight.
Pioneered on the BMW S1000RR superbike, an on-board banking sensor feeds lean angle data into the bike's central computer and that data is used by the traction control and antilock brake systems. That same data is what controls the adaptive headlight.
All this occurs with the bike's central main headlight beam. Two high beam lights with "angel eye" rings sit outboard of that main beam, referencing the lighting elements on BMW's SUVs.