How do you get X-rays to reflect from a mirror? X-rays go through most things and the shadows of bones are caused by X-rays being absorbed, not reflected. The answer is to fire them in at a very tight angle to the surface. In X-ray telescopes, they are called "grazing mirrors" because the X-rays graze the surface. You can see the effect with glass. Looked at straight on, light is transmitted through and you can see what's on the other side, But look along the surface of the glass obliquely and you see a reflection. The poet George Herbert summed it up in a hymn from 400 years ago, before more gender inclusive language I'm afraid: "The man who looks on glass on it may stay his eye, or if he pleaseth through it pass and then the heavens espy".
