I often wonder if Charles knew at the moment, when looking upon the bucolic scenery, that one day the image would become synonymous to many with the advent of the digital age.

he was successful national geographic photographer, so he knew what he was doing when he took the photo, but of course, he had no idea what would happen...

there is nice write-up on wiki

Microsoft said they wanted not just to license the image for use as Windows XP's default wallpaper, but to buy all the rights to it.[9]: 3:37 [24] They offered O'Rear what he says is the second-largest payment ever made to a photographer for a single image; however, he signed a confidentiality agreement and cannot disclose the exact amount.[6][11][25] It has been reported to be "in the low six figures."[4] O'Rear needed to send Microsoft the original film and sign the paperwork; however, when couriers and delivery services became aware of the value of the shipment, they declined since it was higher than their insurance would cover. Instead, Microsoft bought O'Rear a plane ticket and he personally delivered it to their offices in Seattle.[4][9]: 3:57 "I don't think the engineers or anybody at Microsoft had any idea it would have the success it had," he said.