Bug: Images not loading in production environment. Shared hosting via BlueHost.
If the extension is .JPG then it will be processed as text/x-generic. A lot of professional photographers have .JPG as the default setting in their cameras and will send you images with the following extension.
Renaming the image with a lowercase .jpg does the trick.
(It sounds so easy when you figure it out)
The difference in response headers. Here was a thread from 2009 that helped point me in the right direction.
Protip: Set up Hotlink Protection