I am afraid that if you are not using Atlassian Access, your Trello is not connected yet via SSO however it should work when using Cloud. If this is not working the way I can think of is to use Gravatar that might get automatically uploaded to various sites (including Trello that is supporting it)
I have the same problem, my Trello account as an atlassian one (if I want to update my profile it says "This is an Atlassian account. Edit your personal information and visibility settings through your Atlassian profile.")
I have recently change my profile picture on atlassian, but Trello is still showing the old one.
Hello Community! My name is Brittany Joiner and I am a Trello enthusiast and Atlassian Community Leader. I'll be sharing with you a series of videos with my top tips on how to best use Trello...
Connect with like-minded Atlassian users at free events near you!Find an event
Connect with like-minded Atlassian users at free events near you!
Unfortunately there are no Community Events near you at the moment.Host an event
You're one step closer to meeting fellow Atlassian users at your local event. Learn more about Community Events