What does this indicate?

[Dom]

I am seeing this avatar in my notification list.

When I click on it, it is just a thread that has been started by a known member.

What is the significance of this avatar?

 

[BryanM]

I believe that is Reef2Reef.

 

[Dom]

I believe that is Reef2Reef.

Yes, but when you go to the link to read, it is a user.
As an example, it would be as if I posted this question and my avatar was replaced with this:

But when you go to the thread, it has my regular avatar.

It must mean something, and I'm just trying to find out what.

 

[Fish Fan]

Was the "user" Daniel from R2R by chance? I sometimes see that image associated with his account. If not, it could have just been that for whatever reason that user's avatar didn't load correctly, and was replace with a generic Clownfish. Just a guess, of course