Nurses in a medical setting conversing over a plastic cup.
The nurses are eating lunch.
Nurses that are eating lunch would be out of a medical setting. Medical settings aren't a good place for food, and it could contaminate surfaces or be contaminated
One cannot eat in a medical setting because of regulations.
you don't normally see people eating whom they are working in a medical setting. Eating and conversing are 2 different actions.  Eating implies food, which is not usually found in a plastic cup,