If you’re parked on the side of the road and needed more light up front, or maybe fixing something and needed more light. It’s just an expanded field of light. Those along with headlights and cargo lights give an almost 360 field of light (minus the bedsides).
Unfortunate you have to manually move the mirror itself to “aim” them. Also, since GM calls them “high spot” lights, wish they would have put refractors with them and made them almost pillar light esque.