A New (or New-To-Me) Trick for Clouds

Until recently, whenever I would find myself talking to a cloud instead of an avatar, I would nicely ask them to Edit > Appearance so that their avatar would rezz for me. But! Did you know that if you change your own group tag, their avatar will rezz? And if you know this, can you explain the logic to me please? Ha! Well I don't know why, but it works. Happy day!