system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does taking a picture of something on a screen (laptops, cell phones, TV, etc.) cause bad pictures?
gpt
Because what you are seeing with your eyes isn't really what is there.  The screen is rapidly being written, top to bottom, over and over again. It is so fast that to you it looks like any other object, but your camera doesn't "see" things the way your eyes do.  Also, most cameras also do a scan when they take the image, also very fast, but often left to right instead of up to down.  This can lead to some weird artifacts.