This episode contains the biggest unresolved mistery of the series: who os the magical monster queen in the portrait?
There's this queen in the books they mention a couple times called Soupina, the Strange. There are no pictures of her yet she is known as a legend mothers tell their daughters so they keep on track and learn magic.
It seems she wasn't interested in it and prefered to aid mewmans personaly by cooking and shit.
Now, before Slywynne monsters and mewmans didn't really have problems with each other so there were 26 queens (including Lyric and Mo) who could coexist with them, but their data got lost when Lyric burnt the castle and the first Book of Spells.
What if one of the previous queens married a monster and Soupina is the one in the portrait? If she really insulted magic so much, it is posible that the MHC got rid of her (explaining the tragic fate Festivia assured she had) and that's why they feared another monster queen could take over centuries later (Meteora)