This is one of my most favorite pictures. It was taken on the Grande Hyatt in NYC. Twenty years ago I had SKRUB. And a very unusual hard felt pad on a Makita grinder. The windows were first surface PPG Silver. You are looking at a reflection of my feet and the machine used to clear the spot. Reflective first surface pyrolytic hard coats are the easiest to clear. Imagine a building that is supposed to be a bright gleaming mirror covered with a dungy brown pollution. That spot was about three square feet and took a minute to clear. This is a perfect example of what I call light staining. Even though it looks bad.
Henry
