A one-way mirror looks like any other mirror on one side. One side of a one-way mirror allows you to look clear through. The side of a one-way mirror that allows you to look clear through does not act like a mirror. Bob can see Jane through the one way mirror, but Jane sees Jane on the other side does not see Bob in the one way mirror. Jane sees Jane in the one-way mirror. Bob does not see Bob in the one-way mirror.