What does the description of the phenomenon at atomic level look like? I assume that atoms absorb and emit a wave with a changed amplitude. What is responsible for dividing the amplitude level and direction of division?
In case you are talking about a one-way mirror, there is nothing asymmetrical about the material itself. Light can pass both ways with an equal probability. However, if one side is brightly lit (like for example the inside of an interrogation cell) and the other is dark then someone from the bright room won't be able to see the dark side because the reflection of the bright side is too strong.
There are actual optical elements that can make light pass only one way and they are called optical isolators. These use a non-linear interaction of light with a magnetic field in a medium which rotates the plane of polarized light such that light going one way will be aligned with a polarizer at the output and leave but light going the other way will be orthogonal to the input polarizer and will be absorbed.
These optical isolators do only work for a single specific frequency of light at a time and require quite strong magnetic fields around the path of the beam so you could not use them to build something that resembles a plane of "one-way glass".