It means Nympheon is evolving from Eevee, and that was the best place in the page layout to put the arrow.
I will bet you 100 US dollars that Ninfia does not become Nympheon and is not bug type. You have said this in nearly every topic about it, and it's getting old. Nothing even closely resembles a bug.
As far as I've seen, neither you nor anyone else has refuted the evidence (which I gave the last time you said this, and in many other topics), nor provided any stronger evidence, nor put forth an alternate etymology for the name "Ninfia", nor otherwise done a blasted thing to even try to debunk my theory. Calling it Nympheon until we get evidence against.
I suspect it's Normaleon.
Oh, yeah, type name with "eon" at the end, that's clever.
Creator of Jay's Journey (see quote!) "It's not ten years old! Therefore, it sucks!" - Nostalgia whores everywhere