Thread:Extension talk:FacebookLikeButton/Add your own picture and discription into the Facebook-Like

I installed the extension, but when i like my page I got the "Powered by MediaWiki"-Logo on my Facebookaccount. I want to change this into a different picture. How can I do it? That "Powered by MediaWiki"-Logo sucks. And I also want to set a own description into the like. Is there something I can do?