Sewn Chaos worked on Orianna because she's clearly not human, but has that human shape. So making her into a messy and creepy looking doll made perfect sense. She's not fooling anyone with her appearance in terms of being human, but still has that "empty shell" description of where she might've been a human once. I like that, which is why I don't really like the Winter Wonderland skin or that Heartseeker skin, where it loses that description.
More so, you don't get anything like that description with Blitzcrank or Amumu, where that humanoid shape is just simply not there. I do really like those skins, but I don't think it should've been called "Sewn Chaos", maybe something like "Sewn Awakening".
The splash art gave me less "Chaos" and more "Awoke" because it doesn't look like those two are there to cause chaos, but more like trying to live, or about to come to life from being encased in a toy box. But that's stretching it, and I don't think it covers the quality issues which made the skins canceled.
Personally, I love the idea of Sewn Chaos becoming a full fledged skin line, so here's hoping they really do make an effort in making it a fully realised series!