"Stuart" wrote in message
news
I've noticed these being put up at Wood Green and Finsbury Park over
the last week - they're big grey metal panels which seem to be having
a white layer put on top

Are these for moving projected adverts?

I don't know about those stations, but noticed (thankfully silent) video
ads being projected last week at Piccadilly station. There were several
along the platform. I was surprised at just how bulky the suspended
projectors were.