Marilyn says that they do not notice because they are smell oriented. Even humans ignore reflections. In the case of TV, the cat's eye may have lower visual persistance time due to the shorter neural paths. If this is the case, the cat sees the moving scanning line rather than a picture. It looks to the cat sort of like an operating TV set in a scene of an old movie, where you see flickering bars rapidly moving down the screen.
Studios have to use special techniques to make a TV picture appear normal in a movie.
When it sees the image do exactly the same thing, it knows it is a reflection and walks away. It reacts quite differently when another cat is on the other side of a window. Specifically I say Marilyn is wrong because these animals have learned to ignore reflections through kittenhood experiences. Mine always ignores the reflection of herself, but she routinely uses the bathroom and bedroom mirrors for viewing other objects. So here's at least one example of a cat that uses mirrors much like we humans do.