Yea they are messed up.
There are three ways to post pics. Load them up here to your gallery (hardest way). Attach them to the post....like if they are in your phone and you are posting from that. Or last to link to another site, like photobucket or smugmug or Flickr or something. It looks like you are doing the last, linking to another site.
To do that you need to figure out how to get a link from that site that has .jpg or .bmp or whatever on the end.
If I go to my smugmug and look at the page that has my Fonz picture and just post that directly:
https://jimkennedy.smugmug.com/Wizard-World-2016/i-JmNP5WK
It won't show up, but you can click on it. If I use that same link and hit the button on the bottom right that says Insert other media and post that link with 'insert url', it won't show up.
But if I go to my fonz page and get the full url to the actual pic by right clicking on the pic and saying 'get 'copy image address' I get the full url with the .jpg in it. I can just post that into the post, or use the button on the bottom right and insert url.
The key is to use a url that has the .jpg or .bmp or what ever on the end, that is a valid link all the way to the image. Get that and you will be golden.
EDIT. TOOK OUT MY FONZ PIC SO NOT TO MESS UP YOUR THREAD. IT WAS THERE, HONEST.