I got the reference later when I visited this topic:
I believe the changed icons are due to the new login process.
In my opinion, it should happen only once when the member first logs in via the It’s FOSS login. The profile picture needs to be re-uploaded.
A sure shot way to get the same profile picture everywhere is to use Gravatar:
These are sort of universal avatar/profile picture associated with your email address. Many major websites use it to fetch the profile picture associated with your email.
You change the profile picture in Gravatar, and it gets changed everywhere (Gravatar supported websites).
This is what I use and that’s why my profile picture is the same everywhere.
Of course, it is not mandatory to create a new account with Gravatar for It’s FOSS websites. You should be able to manage things from here.