The opening of the tallest hive was not circular like the smaller ones and here is framing some of the 244 busts above the center court representing different building occupations.

An interesting article on “Hive,” which says the installation wasn’t finished in time for the opening since the designers hadn’t realized that the tubes would start leaning inward due to their weight and that the biggest hive is 50 feet tall, 10 feet less than planned. It also says the tubes are Sonotubes, usually used for pouring concrete to build columns in parking garages and other large structures. The biggest tubes weigh 200 pounds. The entire structure is 72,960 pounds.
http://www.washingtonian.com/2017/07/07/the-national-building-museums-hot-new-installation-wasnt-finished-for-opening-day-heres-why/

Colorful paper tubes, posted earlier: