Ok, so it is for the +/- image.
Since the images are not apart of the modification, this means they are being pulled from another source. Possibly your site to track installs? Maybe not. What if that site does down? Then I have a dead modification as it will give me nothing but broken links to the images. In addition has HTTPS taken into consideration? If your serving via HTTP then my visitors will get a mix content warning and not show as a secure site.
I prefer to self host images as I can not predict when a resource will change.
I appreciate the response