MIG wrote:

The thing that looks odd to me is that there's only the one
advertisement. Why would so much space be wasted? Something makes me
think that the wall at least has been put together by repeating one
section.

I don't know about Berlin, but in London there aren't many adverts on
platforms which are neither in Zone 1 nor served by trains towards Zone1.
One advert on such a platform would not be unusual.