I think what you are looking to do (like most people in this forum) is a picture that is a link to your project? If you do
[url=http://destinationurl][img width=x height =x]http://linktoyourimage[/img][/url]
That will allow someone to click the picture in your signature and go to the link of your choice...most commonly your project build. Also, I would try to avoid changing the width/height in the link code. When someone clicks it, it will automatically resize itself to original size....like yours does now.