The link has to end in .jpg/.png/etc in order to embed. The system will edit your post to convert your linked picture to a cdn.discourse.org/uploads/boingboing/ picture a few minutes after you post. If you go to “Edits” under funruly’s profile, you will see “We have downloaded copies of the remote images”.
If you do not want to upload something to an image hosting website, just drag and drop the picture into the reply box.
