Invisible Object in secondary screen

Hi guys,

has anyone tried to hide an object in a secondary view? is it possible? lets say im viewing a card in VR, but i dont want the outside spectators on the reality, to see its content.
I have seen this in games like Onward with its minimap tablet. Any ideas? thanks in advance!

Stereo layers are only visible inside of the HMD if you are using standard mirror modes.

Thanks for the reply mordentral, just to understand better, what do you mean by using standard mirror modes? Without stereo instance? Thanks in advance!