I think this goes hand and hand with the strangers in the mirror, but is a little different.....At times, when I'm in a switch where in my mind, I see my alter also, the next similar, and it doesn't even have to be similar person looks like my alter as a external person...

Ideally, when the time is right you want to make acquainted alters that might not have caught up yet with who they don't recognize. Flockpride, you might want to ask inside, who is this person greeting me maybe it is with an alter's memories, or maybe you just plain don't remember the person....I'm sure you know when you have to get DID involved, some stuff just is...