Is this a rental?

Yes! It is a rental

If the bed will fit into the alcove under the overhang it will look more intentional. Store the ladder in a closet or under the bed until you need to use it.

Storage it is and that's the only way to use it. Rig up a pulley system to haul boxes of stuff up into it. What size bed do you have for this room?

You sure they didn't sleep up there? Then you could have a desk or a couch or who knows what. I wouldn't worry about the look -- hang a curtain from it to give it a spiffy look, or just ignore it.