Click on your name, click 'profile picture', click upload (at bottom). A small window opens up saying something like 'search for file 'BY' upload to beta.myeloma. (it sould say 'TO')
You now have to find were your picture is on your computer.
Try different 'look ins'. Before this procedure if you had saved your picture to your desk top, you would 'look in' desktop.
If you dont want your photo displayed, google 'free avatars'. You can download any of these pictures. Some of the moving ones are quite good – though I decided to be restrained in my choice :). If you do it this way you would 'look in' your download folder.