Everything was in its organic state. That meant that there weren't troops randomly marching in formation, or being instructed to do certain things a certain way, or that there was any need to put on a performance. All the soldiers around him were naturally just doing their tasks. There were some soldiers who were patrolling the place, but most of them were just carrying out their tasks, whether that was transporting goods, making a report, receiving guests or anything else.
Nero knew that in the army, there were more logistics and miscellaneous work personnel than actual soldiers, but even so, the flow of the base felt great to him. It was not the excessive discipline - no, he could have done without that. Or the absolute need to obey orders, if he was being honest.