The examiner rejected it as obvious. More limitations were added that made it no longer obvious. It's the new version that was ruled valid.
Consider (120 years ago) a patent on "using energy to move a vehicle quickly". Well, that's stupid and obvious. But using an ICE to move a car was not. So you add more details and limits until it's no longer obvious.
Consider (120 years ago) a patent on "using energy to move a vehicle quickly". Well, that's stupid and obvious. But using an ICE to move a car was not. So you add more details and limits until it's no longer obvious.