Adding your image to your author bio in wordpress is incredibly easy. All you have to do is create a Gravatar account and make sure you use the same email address that you used in your author profile.
Once you have made the gravatar account and uploaded your image it will automatically appear in your author profile on your blog (can take about 5 minutes).
It’s beautifully that simple.
1) Make your author profile in wordpress
2) Make your gravatar account on gravatar.com using the same email address you used for your author profile
3) Upload your picture on Gravatar.com and complete the process
4) Select the picture on Gravatar.com that you want to use
5) Wait up to 5 minutes for the picture to appear automatically on your wordpress author bio.
Please note you must make sure you have the Show Avatars option selected in wordpress.
This option is found in Settings -> Discussion
What is a Gravatar?
A Gravatar (Globally Recognised Avatar) is an image that will automatically be used for you in many places on the web where you have used an account with the same email address.