Looks like a personalized aftermarket addon? V.W take a lot of care over styling and I wouldn't expect them to add a door trim that doesn't run the full width of the door if that's what the photo shows, because the end taper is there to clear the front fender when the door is opened? It's about the right length for a shorter 4 door car but not a much wider 2 door. It's probably stuck on with double sided body tape which with a lot of care could be removed if you don't like it - depends how long it's been stuck on? Has the car been re-painted? It's the kind of thing body shops might do when asked.
If you're thinking of buying it perhaps you should do some background checks first? Hard to tell with just a couple of photos, but for its probable age, the paint looks surprisingly new. I'd expect to find evidence of normal wear and tear somewhere on the paint work if it is still original.