Sometimes back in the day new buildings were built next to existing buildings that had advertisements already painted on the exterior walls. Then years later the newer buildings are either torn down or fall down due to lack of maintenance and the original ad reappears.
That almost looks like what happened here in this picture which could be the reason what looks to be the original paint is still in pretty good shape.
Here is a link to a picture of a Harness Shop advertisement that was totally hidden until a number of years ago the Chevron Station that was hiding it was torn down before it was able to completely fall down.
Since then it has had a total repaint which I feel was too bad as I kind of liked the original look of it.https://s441.photobucket.com/user/huksybob/media/HOOPFEST006.jpg.html
(Hope the link works..... one of these days I am going to have to actually sign up for photobucket.)