It will make it harder but as long as they show a picture it can be photographed from a screen. I tried it once with a Simpsons fragment and I couldn't see the difference between the original and the "screener" copy. Although some detailed nature scene with waterfalls and winds blowing or an explosion would have been a harder/better test in this case it doesn't matter because we're talking about pictures. So it will raise the bar and require more effort to copy an image probably resulting in less abuse or less intense growth of stolen image abuse.