To keep our websites fast and cost-effective we utilize a sophisticated Content Delivery Network which load-balances all images and files between our 4 datacenters worldwide and serves them from the least loaded datacenter, nearest to the user. Therefore, the URLs of images and files get constantly changed and linking directly to an image or file URL may result in a broken link.
A nice workaround would be to insert the image in a file area and use the file's permanent URL to link directly to it.