On some cars, it’s not intentional. Some cars have daylight running lights and they automatically stay on. It’s suppose to make oncoming traffic more aware of your presence.
Some manufacturers don’t do the full light treatment during the day, but just turn on an auxilary light. BMW uses “angel eyes”
Audi’s started employing the LED’s “evil look”.
I’m sure a few people probably mucked with these types of auxilary lights to keep them running in daylight, just because they look cool (never understood why though)