To add your picture to the conversation piece profile, go to: "edit profile" and "basic profile". There is an option: Your Picture (Entire URL - Picture size is 65x75 pixels). You have to put the URL of a place with your picture... I see that you have a pic on your TW Members Registry- maybe you can put that link? Do you have a homepage or another site which has your picture on? :-) Once you have put the link in this space, you click on "submit".
To be able to see the pictures of all the posters besides their names at the conv. piece, you have to go to "edit profile" and "display preferences". There is an option called "View user's pictures with their posts? (Only when post headers are on the side)". Click on the "yes". Submit. Hope I have helped you! :)