Some websites block hotlinking, which is what we do here when we put the url into the image tags. The only way I know to check if they do that or not is to post it, go back into the thread, and then reload the page. It shows on your computer, because it's in your cache. When you reload the page it ignores the cache and gets all of the information again. If the site allows hotlinking, the image will show. If they don't, it won't.