To have your avatar appear in LeanKit, first create an account at http://Gravatar.com. This is an industry standard services used by thousands of websites to store and display photo avatars. When you create your Gravatar account, you need to make sure that the email address that you use for LeanKit is included among those you use for Gravatar. And you need to be sure the image is rated G or PG. Nothing too racy! Once you have a Gravatar account, your photo will appear on cards to which you are assigned for anyone who has elected to see avatars. This is a personal setting in the options tab of the board. See the attached image.

Note: You may have to 'hard refresh' the page [CTRL + SHIFT + R] on a PC or [COMMAND + SHIFT + R] on a Mac.