The head of a Melbourne prostitution syndicate would monitor the performance of her staff and hand out fines if they did not work enough hours.
Prosecutor Danny Holding said phone taps reveal Mae Ja Kim barking orders about the management of the sex workers.
"If you let them have their way when they're sick, they will have time off," Kim said in one conversation, the Victorian County Court heard.
Another discussion revealed Kim was angry that girls were being given breaks.
One worker, Coco, had swollen eyes after working for six days straight, the court heard.
Mr Holding said Kim would monitor the women's performance "with a view to being able to impose a fine, sack or shift workers" if she was not satisfied.
"There is a level of exploitation that is obvious from the (telephone intercept) material," Mr Holding said on Friday.
Kim recruited workers from Southeast Asia in 2013 and brought them to Melbourne to work in four licensed brothels.
She was not licensed to operate a sex worker business or take any of the earnings.
The 41-year-old has pleaded guilty to dealing with the proceeds of crime, in excess of $50,000.
Her sister, Moonja Kim, 58, Mae Ja Kim's estranged husband Huan Ye, 34, and associate Zhe Fang, 27, have pleaded guilty to aiding and abetting dealings with the proceeds of crime.
They helped Kim run the day-to-day operations of the ring.
The group's legal representatives said the crimes were not the most serious of their kind.
Barrister Anthony Lewis, representing Fang, said the brothels were licensed and the workers were not in the country illegally.
"There was a level of regulation," Mr Lewis said.
Kim lived in a Southbank apartment at the time of the offending, visited a beauty parlour up to four times a week and dined on meals that could cost up to about $2000 a sitting, the court has been told.
She is now working as a kitchenhand and is on bail, with her three co-accused, until the matter returns to court on November 11.
