Click reply as normal, below left is the blue words 'additional options', click on that, then click browse and you can scroll through to choose your photo, then click post. But you need to resize photos to below 512kb - you can do that in the programme where you view your photos. I save any I want to post with a different name so i don't lose the quality of the original. I also save to my desktop so they are easy to find from the browse facility, then i can find them again to delete if I wish.