Are you maybe trying to copy and paste some code to show images? This site does not like that and it often causes issues.
I would recommend you click the little Image icon up at the top of the reply/post box (it is over to the right of the "center justify, right justify, spread text evenly" options), and enter the address there. Or better yet, upload the photo to this site directly (also by clicking that button).
Edit: Here is a photo.
Edited by paneubert - 5/19/16 at 1:08pm