Scientists bang on about symmetry all the time and there's even a particle physics magazine devoted to its name. What we have here in the mirror is a portal based on liquid and reflection, a 3-D version of the quantum mirror in Stargate and lots of other sci-fi programmes, and just because we can't slip a hand in and touch each other's fingertips here in 3-D space doesn't mean we don't have a symbiotic connection with ourselves across the branes of the Multiverse.
Glass is liquid, silver reflects a pure light. Combined as they are in mirrors, this meld gives us a 3-D doorway. Here in 3-D flatland we have no chance of 4-D security clearance, there won't be an access code coming along in this lifetime.
Think about it. Our link to 4th dimensional living space was right there in front of us all along.
Go behind the pics to find out where they came from.
Living as 3-D beings means that we are stuck with looking at 2-D space, so we only ever see a flat picture in front of us which our brain, understanding as it does the role of photons in making things visible, interprets light and shade as it fills up the picture. This understanding doesn't stop the picture in front of us from being flat, and we cannot access matter beyond the surface electron layer, we're not allowed. This is why we can't put our hand through walls, or draw a 4-dimensional object which isn't just a 2-D interpretation of what one might "look like".
Science suggests that dimensions are sorted at right angles to each other, so explaining why they can't be 'seen', along with the curled-up-in-little-packets theory that just wants to tuck them up out of sight, out of mind.
Once we get ourselves to a point where we can "think 3-D" then maybe we can make friends with our Universe in ways we'd never thought possible?