Weird 1.5 bathroom (HELP)

[Sean Steele]

I recently closed on a house and I have this weird 1.5 bathroom upstairs. The bathroom connects to the master and the hallway.

My question is any idea on how to make this look most presentable/functional. My goal here is to BRRR this property and then live in it. Should I close off the door to the master and just make it a upstairs bathroom?

So weird to me its done like this...

(That is not a mirror on the left, that is the door to the master)

Zillow link: https://www.zillow.com/homes/1...