From my news anchor past, I was going to say it was likely either a chromakey graphic OR a filter over lighting. BUT, there's a seam there, so neither of those are the case. It also seems distorted in some areas.

I know we used a lot of giant printed out graphics (think city skylines) which were then mounted. Just sayin'-- it might not be wallpaper, so think outside the box.

Vivienne Westwood?