Detect Facetime screen shots

For all the experience I have, calling my family in multiple IDs, the person only knows the ID that they already have, and FaceTime has no options to automatically reveal the other IDs that person uses.

I wanted to enable some automatic thing like this for myself, because I have 4 different cell numbers and 3 e-mails with FaceTime. Still have not found how to do it.

So for you, the answer is "no, they still only know about the ID they used".

I would try to create a Favorites list in Facetime.

In your Favorites, you can add or change your contacts' photos.