Like a bit of medieval cosplay sneaking into modern infrastructure work. A tiny reminder that history isn’t just in museums... it's literally hanging off our bridges.

https://en.wikipedia.org/wiki/Topping_out#History

the practice of "topping out" a new building can be traced to the ancient Scandinavian religious rite of placing a tree atop a new building to appease the tree-dwelling spirits displaced in its construction... The practice remains common in the United Kingdom and assorted Commonwealth countries such as Australia[7] and Canada,[8] as well as Germany, Austria, Slovenia, Iceland, Chile, Czech Republic, Slovakia, Poland, Hungary and the Baltic States. In the United States the last beam of a skyscraper is often painted white and signed by all the workers involved.[7] In New Zealand, completion of the roof to a water-proof state is celebrated through a "roof shout", where workers are treated to cake and beer.[9]