Bright lighting is typically an artifact of the commercial property insurance policy in effect (namely, "Protective Safeguards"). It's asking you to demonstrate that you've done enough to create a barrier towards theft/loss.
It doesn't have to be really bright lighting but that's the easiest thing to satisfy the underwriter's request, and as a result, the cheapest to implement.
It doesn't have to be really bright lighting but that's the easiest thing to satisfy the underwriter's request, and as a result, the cheapest to implement.