Cannot post an image to /w/ - duplicate file.

I know for a fact that the thread has fallen off the end, but I can't repost the image that I posted to it last night/early this morning, apparently right before it fell off.  Consider this more of an error report than a question looking for a solution I guess.

how do you post in a thread for a second time without having to post the picture you attached if you had a pic for your first post???