The photographer has listed the names of specific aircraft. Remember you are in competition with other travel photographers who have also photographed in the Grand Canyon National Park, San Francisco, or Jamaica. If you have them but haven't listed them, you might miss a sale. Incidentally, listing in alphabetical order is not necessary. If you searched through picture files, relying just on the image in front of you, in some instances you wouldn't be sure if the image in the picture was a cat, and specifically a Siamese cat.
Images take up considerably more space on the Web than text, too.
The photographer would need either to buy a quality scanner, or to pay fees to have each of their images scanned.