Model is a bit different, but i don't see anything else that differentiates it drastically from all other Anivia skins. Particles will probably be different and stuff, but Anivia is not a champ that you can makes skins for easily.
She's a... giant, talking bird. You can't exactly bypass that and make a new themed skin. Examples of good skins that work outside of the champ's initial theme would be Mecha Kha, Soul Reaver Draven, Rageborn Mundo and a few others. They're different enough because their champ archetypes/themes enable them to design something like that.
Another champ with great theme variety would be Jayce. If Riot never thinks of making a Transformable Jayce skin, then i'll be really dissapointed. I mean, his kit works in a way that switching between his modes would enable Riot to make him theme-class skin(like Pulsefire Ez) that transforms him from an airplane(ranged) and bot mode(melee).
Bleh. I dunno why i wrote this much. tl;dr - Ain't feelin' that Anivia skin.