I can see where reposting a picture can be done without prior knowledge that it was previously posted. Seriously, when a thread is hundreds or even thousands of posts deep, I am not going to fault anyone for not being aware of every picture that has been posted. I know I have done it myself, but usually with the purpose of using it as a prime example of something I wish to comment upon, yet still, we all know this is apt to occur, especially when you are actively involved in multiple threads.