Hi Monika -- OK, I see what's going on. That is not a valid link to an image item on ArcGIS. Links used to reference images or embed content should never contain a security token since tokens expire and are only valid for certain users/situations/times. You can get a proper image link by following the process in this blog.
It's no longer needed for troubleshooting since we've found the issue, but that link you provided to the web map isn't valid either. Web map links will always contain an ID, like this:
http://www.arcgis.com/home/item.html?id=f35ef07c9ed24020aadd65c8a65d3754
You can get this link from the web map item page or by using the Share button in the map viewer (which gives a short link that expands to the link that contains the web map ID). Sometimes you'll see the web map ID in the address bar when using the map viewer, but I believe it depends on how you opened the map.
Owen Evans
Lead Product Engineer | StoryMaps