tauromachine

One thing that's bugged me about photo slideshows on the Apple TV is that it seems to sync two copies of every image in iPhoto - one normal and one at a lower resolution, like a thumbnail version. I haven't seen anything in the way of people mentioning this in discussion (though I can't honestly say I've spent too much time actually looking) and I was wondering if anyone knew anything about it and possibly find some clue about how to stop it from happening.