So why is natural light so hard for a robot? It starts with the fact that they have cameras. And like any camera, they function best when the light is even and predictable. Here is a shot taken by a robot at the venue that demonstrates:

Look at the goal post on the left. It looks mostly white but is actually yellow. People are really good at figuring out that it is actually a yellow goal post, but it isn’t easy at all for a robot.