Taxi lights flashing

Just out of curiosity … Why do taxis that drive the Toyota Camry have their back lights flash occasionally? It’s not the hazzard lights, I think it flashes like that when they brake, but I am not sure. I’ve noticed this on Abu Dhabi taxis too, which drive the same car. It’s a bit annoying and sometimes it dazzles me! What the hell is that thing?!

EDIT: thanks for the responses, everyone!!!! 💕