Plenty of cameras and webcams mirror footage because they are cheap (less lenses/mirrors) or that it barely matters in most cases. Most people never notice their own webcams are reversed, and even fewer understand that camera lenses are not created equal and don't match how human eyes distort what we see. Edit: Also another reason to flip images is to "fake" which hand is represented, skilled artists would make their characters left handed so when re-printed the characters would be right handed in the final product.