click on PROFILE on the top of this page,then:
scroll rite down the page wich opens up and u will see a subhead - AVATAR CONTROL PANEL
then, you have the option of either uploading ur own avatar from ur pc, to put a link of a picture already uploaded on sum site, or to choose from one of digit's own collection
PS - Only one image can be displayed at a time, its width can be no greater than 80 pixels, the height no greater than 80 pixels, and the file size no more than 10 KB.
PPS - those 'personalised icons' under the username r called AVATARS