In the previous versions, it used to be an empty room.
Apparently, in V6, there was an NPC in there. Also there was a door identical to the nexus next to the door there as well…
Specifically, I heard that it was the flower kid NPC.
The middle room was the one with the flower girl, the last and first ones led to the same empty room and you would come out of the first door in the hall, despite entering through the last one.