This website uses universal display picure feature from Gravatar, a globally known avatar service used by millions of websites and billions of users worldwide.
To have a profile/display picture on MyRatna, you may set a profile picture on Gravatar which will stay common for a lot of other websites such as stackoverflow, github, american idol, disqus, and any and all websites making use of wordpress.
You just need to make sure you sign up on gravatar using the same registered email id you have on MyRatna.com
Guide:
How to set pictue on Gravatar