In Image Manager, you have the option of setting a "Type" for your assets. You can find this setting in the "Edit Details" tab.
Here is what the options mean.
Photo and Video
Any photo or video created with a digital camera.
Film (see search results)
Any photo or video created with (non-instant) analog film and digitized with a scanner or DSLR.
Mobile (see search results)
Any photo or video created with a mobile device.
More than one medium or material combined into a single digitized artwork.
Graphic design or digital footage manipulated to give the illusion of motion.
Any photo created with instant film and digitized with a scanner or DSLR.
Illustration (see search results)
Digital or hand-drawn artwork submitted as a jpeg image.
Digital artwork where visual elements from separate sources are combined into a single image. Includes 3D render.