This little tool is generating image with JSON data. Again with the same json data, it is routing the fixed link structure depending on the condition. The main reason for doing this tool is to use dynamic data in problematic areas such as mail body.
You can convert the data you receive from the database into json, making it an email banner / dynamic signature as it is in this example.
You can check live sample from here, http://www.salihtalay.com/tools/dynamicImage/