It shows a model of the World Trade Center twin towers with smoke pouring out.
The float was put together by the Valparaiso Republicans and you can see video of it here:
The Valparaiso Republicans have limited comments on their Facebook video, which they have described by writing: "We worked so hard to show our love, respect, our sorrow and respect to all the 9/11 victims, the soldiers who died in Afghanistan and our first responders. #neverforget #america"
The float was part of the 40th Popcorn Festival.