Below the star is reflected over the line. Clearly this is not same as rotating by 180 degrees. It seems one star is showing the front face and the other star is showing the back face. How does this information represented? The star in 2D has to move to 3D to finish the reflection. Saying $A$ and $A'$ are at the same distance from the reflecting line seems insufficient to fully represent the reflection.
I have been watching this video and it kept me thinking about how a solid shape would look after reflection over a line/plane in 3D. It doesn't look that simple... Any help with explanation/good links appreciated very much. Thanks!
