I'm in 2 minds about filtering out your own username... once half says sure and the other half says keep it's integrity - but since this is specifically a shout out tool I think your right. I'll sort it on my next commit. It works for images on twitter i.e.

but not for the "card" previews (note the white space below)..

Your welcome to, it's why I made the tool. I'd be keen to see how it handles... I'm still running on a free heroku dyno and to be honest I was suprised the tweet tool ran at all but it seems all right. If it takes off I'll shift it onto one of my production machines.