One thing that confused me was Piper introduced herself as "Pyperia Ashrynn Elvenastri" to Zarya in episode 8, but the Dragon Disk called her "Piper Willowbrook". I assume that the Dragon Disk would use her legal name (it calls Em "Emerald") so why wouldn't it use Piper's full name? Here are my theories.
1. It was simply a mistake. I'm sure with how many people work on an episode, and how quickly they may work on episodes, I'm sure it's easy to add that joke, forgetting what the Dragon Disk said.
2. The Dragon Disk didn't actually speak in the show, and that part was mostly for the audience. It's possible that Arkayna (who studied the Mysticons) told everyone off-sceen what Mysticon they were. However, if that was the case, then why did they have to include it in "The Edge of Two Morrows", even though most of the audience wouldn't need it (though it's possible they just kept it to fit the whole "similar to the first episode" idea).
3. Piper was given the name "Pyperia Ashrynn Elvanestri", but her name was legally "Piper Willowbrook". It's mentioned in the novel "The Diamond Curse" that Piper has a memory full of holes, so maybe she doesn't remember her full name. However, if that's the case, then Zarya got really lucky giving her the nickname "Piper".
I would love to hear your thoughts.