At the risk of getting railed yet again, I have an idea I'm curious about.
What about a mask that reflects the wearer's memories onto the surrounding environment? Outsiders can step into the memory field if they're within a few meters or so. The mask may have some sort of vague sentience, even telepathically whispering to the wearer or observer in voices of their loved ones. Perhaps the mask, while somewhat sadistically, feeds off of the wearer's brain waves which it then uses to perpetuate and strengthen the illusions? I don't know, I'm just throwing darts.
They can contain it fairly easily; a simple, completely sealed container of sorts. Hell just a fancy box even.
I've seen a few mask SCPs but none quite like this—if there is one like this, I apologize beforehand.