There are two ways to show pictures. If you upload it directly from your computer using the "Add an Attachment" feature below, then it adds the little green camera icon to the title of the post.
If you insert a picture by using an image hosting elsewhere (Photobucket, yahoo, Flickr etc.) and the IMG code that looks like
then a camera won't show up in the title of the post, so you really have no warning if a post has a photo ahead of time or not.