I run into a lot of broken images, as my work's firewall/proxy blocks access to a lot of the popular file sharing sites (dropbox, drive, etc).
You can right-click on the broken image and do "Copy Image URL" (or something to that extent) to see if the image might be hosted on a site blocked for you.
You can right-click on the broken image and do "Copy Image URL" (or something to that extent) to see if the image might be hosted on a site blocked for you.