Lookback currently uses a 3rd party site, Gravatar, for storing and displaying your profile picture (aka avatar) in Lookback.
If you want to update your profile photo, you can do so by following these steps:
Log in to your Lookback account
Click on your name in the top-right corner to access the menu
Click My account in the menu
Click Change picture underneath your current profile picture
You'll be re-directed to Gravatar's Login Page
Log in to your WordPress.com account
Follow the instructions on screen to select and use a new photo
Now your new photo should be reflected in your Lookback user account!
If you run into any problems on Gravatar's site, please see their support section for assistance.
If you're still stuck and need help, feel free to reach out to our support team using the chat bubble in the lower right-hand corner of this screen.