Redditor Corttana and her husband made these mirrors for their Portal-themed basement. They’ll take you to where you’re already at. They achieved the vortexy Portal outlines simply by looping up appropriately-colored rope lights at the back of each mirror.
Check out Imgur for more pictures. Corttana really should go try Redditor brownmandm’s suggestion – use angled mirrors so that when you look at one mirror, your reflection comes out on the other mirror. Here’s an even better idea: just hire identical twins to stand in front of the mirrors whenever you have visitors.