It would be a good reason as to why it has a lot of similar characteristics to Jigglypuff and Clefairy, with them both evolving that way. I'm sure someone will argue or call it stupid, but that's just my personal thought on the matter, based on the given info thus far.
Founder - IRDC AND Fluffy the Friendly Deathclaw Fanclub ULCE#: 9,426 of 53,160; Misty is mine!
I'm gonna guess Dragon and it can evolve based off the third gen model of either Coolness, Toughness, or Beauty....
My reason for Dragon. First it has fangs which none of the other ones have shown before to my knowledge (nor in the picture with Ninfia's release). Also Dragon was the last type of the original Special though that's not much of an excuse at this point and time.
As per the evolution. In my eyes it looks like Milotic with the color scheme and the idea that it has a Bow might indicate that Contests come back. I would take this with a grain of salt cause its pure speculation but it does seem to have an adequate theme to it being a new evolution method to an extent.
The only other thing I could possibly see it being is a Normal Evolution but where you can give it items and it would have a Secondary type of one of its other evolutions... I.e.
Ninfia @Thunderstone --> Ninfia Normal/Electric
That could be another new theme to the Eevee Evolution scheme.
Bow-ties are typically symmetrical, where as the ones here are obviously designed to look like butterflies, with the bottom half being smaller. There's not a standard "grotesque" bug like appearance, but the eyes, bow-ties, visible fangs and the tendrils definitely give it a bug/butterfly like vibe and the name seems like it could very possibly be a play on nymph (beautiful bug/creature), which would suits its appearance.
I'm firmly part of Team Bug, but anyone saying it definitely is something or definitely isn't something are jumping ahead of themselves a bit too quickly. There's reasonable evidence for all 4 cases.