PTowns- thanks for planting this question in my head, because I’ve been wondering the same thing myself. After scouring every square inch of this site for hours on end, I finally gave up and messaged the staff. Mike emailed me back right away, and here is what he shared:
1. Go to gravatar.com
2. Create an account using the same email as you do for this site
3. Load your profile pic
From there, the site will automatically pick up the pic. As you can see, it’s now working for me.
To the admins, I recommend you add this to the FAQ.