Ah, character episodes. You’d think they would be our bane, since we’re definitely in love with the lore of the show. The characters give meaning to the lore though, so we’re quite happy to see Jamie return (especially if we have an episode like Reformed coming up with a premise that implies some good chances for lore).
Just a place called Kansas
Steven Universe takes place in an alternate history of Earth—we don’t necessarily need Ms. Sugar to tell us that (though we’re glad she did!). There had been a few subtle signs in the show: Arcade Mania had the Department of Justice seal and the face on the quarters be very different from our world; Watermelon Steven includes a three-dollar bill; sharp eyes in Jailbreak and Say Uncle will note that Florida doesn’t seem to physically exist.
Online, the worst-kept “secret” of the show was widely known: Beach City is in the state of Delmarva, which in our world is a region that is part of the states of Delaware, Maryland, and Virginia.
All of these were background elements though. You could easily miss them because the show called no attention to them. In Love Letters, though, we got something actually mentioned in dialogue: Kansas is America’s film making hub in Steven Universe.
There’s a small chance that Hollywood is still the real place to go to be an actor, but it’s very unlikely: he was able to get numerous auditions, and Connie immediately recognized Kansas as a place for “thespians” to be.
California does still seem to exist physically (there’s no incursion of the sea into America’s west coast, and Baja California serves as a good marker), so for whatever reason Kansas developed as a film hub rather than California without becoming the new west coast. Or perhaps the state lines are drawn differently; the same differences that cause Delmarva to exist as its own state could feasibly allow Kansas to somehow encompass the west coast as well.
The water bear
It was really brief and not commented on by the episode, but we did get to see Garnet fighting what appeared to be another Gem monster in this episode (the gem being on its face). It very clearly resembles a tardigrade (commonly known as a water bear), and while Garnet carried it out of the ocean to pummel she didn’t seem to think it enough of a threat to defeat and bubble.
It’s always possible that it’s not a proper “monster” (i.e. the thing on its face is not actually a corrupted Gem’s gem), but either way it’s a very interesting thing to note. The Crystal Gems have fought water-based enemies before, but this one seems to have taken its inspiration from a very, very small creature indeed.