Accounting aside,
All of the Crew Appreciation and Service Charge payments made by all guests on all ships in our fleet are pooled, net of credit card transaction fees. The pooled funds are distributed throughout the year in the form of compensation, including bonuses, to crewmembers fleetwide who interact directly with guests and/or behind the scenes throughout every cruise, including those in the Bar, Dining, Entertainment, Housekeeping, Guest Services, Galley and Onboard Revenue areas.
https://www.princess.com/html/global/disclaimers/crew-appreciation/