It only shows an officer's cabin I think, I wonder how those of the rest of the crew are.
Oh, and with any luck, a porthole.
A head, 2sqm/20sqft or so, shower, toilet, sink.
Neat and tidy, but by no means luxurious.
Goliat is a very modern FPSO design, however. My colleagues' experiences in other floating rigs around the world, which are usually built from converted tanker hulls, are more like what you describe, especially below the equator. For contractors you might be lucky and get a double cabin to share, but cabins might have up to four bunks. Definitely don't forget to pack some flip flops or crocs for the showers!
In the end why not provide decent amount of space for crew as there isn't really any that valuable use.