What you see is the evolution of Square, a newish payment system - starting with the extreme left and going to the right, with today's Square under the row. A photo I took on Dec. 3, 2011, at the San Francisco HQ of @Square - http://squaredup.com - on a visit with the CEO and founder of the company, @Jack (Jack Dorsey - creator and chairman of Twitter) and @KLuo (Kay Luo), head of communications (and formerly with LinkedIn). PHOTO: @sree (Sree Sreenivasan) * sree at sree.net - FEEL FREE TO USE WITH CREDIT.