Your profile image is not only used on your Captivate account, it's also what is used on your podcast website either via Captivate Sites or via Captivate Sync™ on your own WordPress website.
To change your profile image:
Click on your name, in the top right hand corner of the dashboard.
Click My Account, beneath your name.
Click on Upload New Profile Picture.
Find the replacement image you want to use.
An Upload Profile Photo window will appear.
Adjust the image to suit.
Click Save Picture.
Scroll down to and click Update My Account.
That's it - you're all set! 👍