Elevator operators, and "starters" in old-time NYC office buildings

Whenever I watch The Apartment, I notice this one scene near the beginning where Shirley MacLaine’s character, an elevator operator, is letting her elevator fill up on the ground floor, and apparently isn’t allowed to start the upward journey until a superior, apparently called a “starter” says it’s OK to go. I know being an elevator operator wasn’t the best job in the world, but they couldn’t even start the elevator until someone told them to do so?

Also, at one point Shirley MacLaine says something about possibly being promoted to starter. Did most manual elevator staffs also have starters?

It certainly wasn’t in all elevators, but probably was used in office buildings.

The point was to keep the elevators moving smoothly during the morning rush. The starter would check to be sure each car was filled before sending it up. Other than the morning rush (and perhaps the evening rush), there wasn’t really much need for a starter.

Store and office buildings in Chicago circa 1930 and later had elevator operators and starters. No push button operation. The operator controlled the ascent and descent and levelling at each floor by means of a rotary controller device. In retrospect it may have been a rheostat for direct control of the hoist machine or by some indirect means.

The objective was to move customers/personnel efficiently. With only a few persons on an elevator and no more in sight the starter would send the few on their way. During sales or rush hour they would urge patrons to get one and off quickly so they could dispatch the lift.