Images are inherently viral. They're easier to link to, re-post, retweet, &c., than text. They work on any device and in any browser. They're easy to save. The

Images are inherently viral. They're easier to link to, re-post, retweet, &c., than text. They work on any device and in any browser. They're easy to save. They can be made more pretty than text and (although not necessarily the case here) the "A picture speaks a thousand words" feature means they can communicate ideas/concepts more efficiently.