I think it’s just a corridor.

I don’t think there’s anything to do with it, it’s just a quirk of level gen.

There are two doors for entering it. No special room has a two door entrance.

This threw me for a loop but after looking at the comments, I think it’s the minimalistic version of this taken to its extreme (by chance.)
Edit: cool to see though, thanks for sharing.

Sometimes the ledge with a chest is just out of view and you won’t see it until you get closer.

Other times, it is just an empty room waiting for you to rush in and fall to your death.

It will cost you to find out.

A potion of levetation, a torch to see further, etc.