When replying to a post, as I am doing now, look down under Additional Options. See where it says 'attach files'? Click on 'manage attachments' and choose the photo you have just saved, then click 'upload'. Your photo will appear in your reply as a thumbnail. Here is another screen shot (a screen shot of my screen shot - this is getting weird ). And note, I am on an ipad, which is why you see the keyboard at the bottom.