Contractors were out several days ago polishing the copper wall. Now it can age gracefully without any excess materials that might have been dripped, splashed or blown against the wall with the construction of other parts of the building. Doesn’t the rock look nice along the bottom? This will help the water drain when it rains. Just the rain basin to finish and this part of the job will be complete.
For some trivia, look at the picture of the rocks on the west side of the wall. The drain in the wall is called a lamb’s tongue. Use that bit of information at your next meeting or social function!