The Test was kind of an important episode for us. The first test was taken at the site’s namesake, after all! The preview was enough to make it clear that there was no funny business involved with the lunar sea spire, though alas a magical resurrection doesn’t seem to be in the cards.
As for the titular test in The Test? Ah, it was a good one, and like always it gave us some good material to comb through looking for clues about the show’s lore.
The metaphysical properties of the temple
We don’t spit on metaphysics and neither do the Crystal Gems. When they need a special testing room for Steven they don’t have to go to work on the beach: it’s just a short (or so we assume) time spent in the temple and they’ve conjured a room out of nothingness for Steven to use. We actually get to see where the room is set, and it’s just in a black void. There’s obviously air, but there’s nothing visible; if there are space limitations in the temple (not a guarantee since it’s in extra-dimensional space), then the Crystal Gems certainly aren’t in any danger of running into them any time soon.
The level of control that the Crystal Gems were able to exert was also quite exact: solid matter was made perfectly invisible, while other objects that appeared solid were completely insubstantial. Even the behavior of objects which should be operating on gravity were perfectly controlled. There was no way that Steven could get hurt during the test, and Garnet was quite confident in that fact.
Presumably the Crystal Gems can place anything they want in the temple. It was already easy to assume that their rooms were very customized to their personal preferences, but now we see just how easily they could change their rooms if their whims changed. Either the test they made for Steven can be easily removed or altered into any form, or space is a non-concern and they could simply make new rooms for themselves. It’s certainly possible that something, once made, is immutable and that there’s a finite amount of space in the temple, but the Crystal Gems didn’t have to think very hard about making the test for Steven.
The empathy of a true leader
When Steven finds out that the Crystal Gems made a fake test for him Steven is upset, and not without reason. However, after listening to them privately state their reasoning for the trickery and their self-doubt about their ability to raise him, Steven decides not to reveal that he is aware of the deception. Instead he takes a charade that was meant to boost his confidence in his abilities as an adventurer and uses it to boost the confidence of the Crystal Gems as caregivers.
Every time we hear about Rose Quartz she seems to be a larger-than-life figure. Amethyst knew she would have no trouble dealing with the Red Eye that they couldn’t figure out how to beat, Garnet talked about how great her empathy was, and Pearl clearly wants to respect Rose’s “most precious sanctuary” as much as she respected Rose herself. Both Amethyst (directly) and Pearl (while projecting) make it clear that Rose Quartz was the heart of the group and that without her the Crystal Gems are lost.
Steven doesn’t just possess the rose quartz gem (though it seems to assure him to be amazingly powerful): half of his personality is gifted from Rose as well. He may look to the Crystal Gems for guidance now, but some time (perhaps even during the show’s run time) he’s going to become their leader; he’s taken his first real step towards leadership of the team by understanding the needs of his team and putting them before his own.