Reminds me of the tradition of topping out a finished roof. You often see 100m+ skyscrapers with a pine wreath hanging on top as if we were still worshipping some forest gods.
https://daily.jstor.org/the-horse-skulls-hidden-in-the-dance...
Where in the world is such a thing a frequent enough sight to say that?
https://slate.com/human-interest/2013/12/why-do-construction...
It's quite bizarre as when it's dark (and days are quite short in Scotland at Xmas) you can't see the crane just this lit up Xmas tree hanging in space above the town. It's very cool.