I was underestimating photos. Maybe you were too.
People do love pictures. The biggest sites in the world, namely Facebook, are mostly about pictures.
And tech is helping all sides of this — more screens (phones, tablets, glass, watches, projection?, surfaces abound), more battery life/more on-time (tabletop digital picture frames), more connected time (wifi, mobile) so you get new pictures more often, and of course more and better cameras (iPhone 5s is as good as my Nikon for 100% of what I did the last three weeks on a vacation, and it was faster in low light).
So many more pictures taken, shared, and viewed.
Flickr, and Facebook, and Instagram must just be the tip of the iceberg. There must be sooooo much more to do with pictures.