Edith Santos, a 72-year-old who's been with the Marriott for 24 years, says if she saw a guest leave their room in the morning, she'd know that she could get in and clean. But she's not allowed to do that anymore — she has to follow the app. And there's no way for the app to know if a guest has left for the day, which means it might give housekeepers an assignment all the way at the other end of the floor, only for them to knock on the door and find out that the guest wants them to come back later.