After Storm in the Room we know more than ever about how Rose’s room works, but we also learned that it’s still a huge mystery to us.

Each episode it has been featured in has told us more about the room:

• In its debut episode, Rose’s Room, we saw the basics: its limits in processing capacity, how you can’t eat anything inside it, and its predilection for not knowing what you actually want.
• In Open Book, however, we saw that the room was actually quite capricious about its ability to follow instructions: while it knows exactly what Steven thinks about the end to the Unfamiliar Familiar series, and exactly what Steven thinks Connie’s outfit will look like, it still gets hung up on Steven’s exact words when it tells figment Connie, thinking she’s real Connie, that he doesn’t want her to just do what he wants.
• Finally, in Storm in the Room, we see the room conjure another figment, and we’re left wondering just how authentic its portrayal of Rose Quartz was. We also see a key fact: that while there is ambient light in the room, a cell phone’s camera can’t see anything that’s going on in the room—everything except the real people in it is a black void.

The black void may very well be the biggest revelation, and it sits nicely with its incomplete mind reading powers: the room is apparently able to both write to and read minds, showing them the simulation while reading Steven’s desires from it.

Even its confusion over exact words can be understood a bit if the room is viewed as keying in on deeper desires than what Steven is able to articulate (he really did like the ending of the book, and was bothered by keeping the secret, even if consciously he had just decided to go with Connie and make a new ending; the room also put Steven at ease about Rose, again only doing this after things went off the rails).

So we at this stage know some, but not all, about how the room works. Maybe once Steven gets better at operating it we’ll have a better understanding of how the room interprets commands, but until then we’re left wondering what the void as seen in Steven’s phone means about the rest of the temple.