Why does Sivir Has a better recall animation then Diana in this skin line?

I don't have facebook. Do you have a non FB link to it?

That being said my guess is that 'better' is a matter of opinion, and you just prefer Sivir's. I assume it's a new skin line since I don't know a skin line that Diana and Sivir share.

EDIT: Found it. For one, generally a organization's skill in an area (except Riot and bug free) usually increases. So since Diana Blood Moon is a lot older, it's just a testament to the skills the skin devs have now! That and potentially price differences.