For the most part, these photos are not designed to document an occasion. They have become a visual shorthand that is at once more emotionally resonant and more efficient than the words I might once have used to express the same ideas. This shift in the nature of communications will have a substantial effect on culture, business, and politics. It’s already reshaping entire industries from advertising to journalism to fashion. It’s powering political campaigns and will help decide elections. It’s changing the American approach to foreign diplomacy. It’s redefining art and our relationship with the cultural institutions that embody it.