Maybe the place was a courtesy prayer room for Islamic visitors.
That’s a reasonable hypothesis.
Somebody sent a drone over to take aerial video of the pedo island the other day. The footage is on youtube. They got a close-up inside the window of that structure. There are a couple of soiled mattresses on the floor and it appears to be under construction or remodeling of some kind. Among the many mysteries, one wonders if that room has been used recently at all. It is reported that the dome blew off in the last hurricane.