Profile picture - scope of access documentation/guidance ?

Hi 

Could anybody point me to any documentation (or other authoritative sources) which clearly states who can see the profile picture of a Teams user under all variations of Teams operational context (for example, user is an internal user not in a meeting, user is a guest user not in a meeting, user is an external user not in a meeting, user is an internal user in a meeting, user is a guest user in a meeting, user is an external user in a meeting, user is in a chat... et.al.)

I'm looking for any unambiguous, accurate statements which can help us to inform our organisation's users about who will be (or is) able to see their profile picture, and when.

thanks

Robert