I thought I'd solved it... with a factory reset of the phone, BUT... No!
Initially after the reset & adding back the email accounts all, once again, showed a "profile image", specifically the initial letter of the account name.
Then after a little while the images disappeared, reverting to the blank circle shown previously.
Weird!
Strangely enough, incoming emails do show the, what I'm calling a, profile image.
I can't be the only person to have this issue!
Virgin Media pls respond.