Their visual similarity makes it hard to watch Olivia in anything and not imagine her as an inferior Summer Glau. That is not just when it comes to acting or general talent, but also looks. Olivia is not bad per say, but you would have to be utterly insane to consider her a better actor than Summer. I could see why some could prefer Olivia's looks I suppose, but both are very close.
Disclaimer: The following is only my own opinion and I don't want to start a fanbase war:
Summer is so much more beautiful than Olivia that it seems even insulting to Summer that she has to compete with Wilde in a beauty contest.
Olivia just lacks everything that makes Summer beautiful seriously.
I know people cares nothing about whats true or not but I'd not support helping Olivia gaining any more undeserved support because somebody in Hollywood wants to make her a super star for some reason. So I'd suggest placing it somewhere where Summer wins.