That is awesome!! Even if it does not serve a purpose, I would love to see it back in the game. Maybe it can show the traffic of the store!! that would be cool!
It used to show number of citizen wondering around depend on the supply and demand bar, and get crowed when demand is high, and number of shafts depend on how many of the 9 slots were taken. I believe the factory also had a tab showing their size with different number of machinery.