The reply above was posted from my Iphone, you write your post, click on the + sign up in the page and then on *image link*.
You paste the url of the photo you want to add - i use photobucket - and here you are, it's the same way you use to add photos on the board from a normal pc.
I did write my reply, close the Dis application, open the photobucket app, copy the url, open again the Dis app and my post was still there waiting from me.
I then pasted the url and here you are