looking at your login page, the user ID iOS saved to a session named:
SecurityAssist_UserID
create a new recordset for the users table, in the filtering section set it to filter the UserID column Equal to Session "SecurityAssist_UserID"
use that recordset to set the image source similar to what is described in the Database starter kit tutorial:
http://www.webassist.com/tutorials/Getting-started-with-MySQL-and-dynamic-websites
On the page you wish to display the image