Self-contained room is a popular term in the rural towns. Interpreted literary, it means the room has everything and anything you need from food to bathrooms, more like an egg or womb.
The term self-contained has been there since my childhood. Curiously, 5-star hotels do not show off their self-contained rooms, yet you can be served food in your room. I however doubt if you can get a decent meal in most “self contained rooms”.