Those blocks are reputation.
You gain reputation points whenever you receive TR, and whenever anyone leave "rep" as most call it.
Someone leaving you a positive TR as an example gives you 10 reputation points.
You can view all of your threads that have been given positive or negative rating in your usercp, as well as the exact number of points that you currently have.
The little icon to leave reputation is the scale that you will see on everyone's posts.
Stephen