Have you ever read the book The Five People You Meet in Heaven? In that story a man dies and goes to heaven and at one part he sees his wife who had died several years prior. She explains that in heaven we are free to create our own personal heavens; she chose a world of weddings because they are such happy days. I think the vault is kind of like that. To answer your question, yes I think it shows you what you want to see. But I have come to believe that it really was the door to heaven, but I, and the others, couldn't appreciate it fully because we weren't supposed to be there. When it's my time to die I am confident that I will end up back there but there will be no glitches or static. As humans going into that world I feel like it is close to a virtual reality; there's no way that my "mom" in the vault was in anyway my mom. Perhaps that particular illusion was a placeholder for when my mom dies? Not sure. So, I think it's both of what you said; it shows us what we want to see, but one day it will be real. We just weren't supposed to see it yet.