RE:RE:Level III would agree Level II "may" show retail orders and interest because retail orders tend to use stops and limit orders more than a broker, but, ....
big brokers selling any amount of size DO NOT telegraph their intentions with limit orders. Maybe as part of an iceberg order that keeps getting replenished but that's it. instead, they pounce from time to time when conditions seem right.
IMO, that is why you have to be very careful when very little shows on the ask, or the bid. It can be a trap. You never really know what big orders are waiting in the background.