I know. The shaping of the perimeter of the "patch" was definitely thought about and done quite well by someone possessing the right tools for cutting leather of this thickness. I suspect that the owner wanted to maintain something identifying this as a COACH bag (other than the absent removable hang tag). And for the "patch" to have stayed affixed for this long hints that whoever did it used adhesive that was better than the one COACH employed for its glue-in registration numbers (that are often found missing by now).
That is a very weird thing to do. I cut out a Coach creed pre serial number and turned it into a bookmark LOL. But the bag was completely ruined before I did that so I wanted to keep a part of it. I didn't cut it out as nicely as that though.