Well, I'm not really sure about this particular mod, since I'm not using it. The one I'm using is
here.
However, I'll tell you how I managed to make it work with it.
In the option where the mod asks you for the name of the tab, just add the following before it.
Code:
<img src="path_of_image" border="0" align="top" alt="" />
Make sure to insert the path of the image you want to show. It works for me. 