Topping Out

Can you see the tree on top of the almost complete Westfield building? It think it must be for the topping out ceremony. As Wikipedia explains: In building construction, topping out (sometimes incorrectly referred to as topping off) is a ceremony held when the last beam is placed at the top of a building. The term may also refer to the overall completion of the building's structure, or an intermediate point, such as when the roof is dried in. A topping out ceremony is usually held to commemorate the event.... it usually includes the placing of an evergreen tree upon the structure to symbolize growth and bring luck.