In 2005 Steve Jobs wandered into a 19-year-old designer's office and spent the afternoon making faces into a webcam. The designer was Mike Matas, who kept the photos on his hard drive for six years and posted them the night Jobs died. The silly app Jobs was testing had a serious job. Photo Booth existed to sell a camera. In 2005 a webcam was a $149 accessory called iSight that almost nobody bought. Apple wanted to build it into every Mac, and a built-in camera you never use is just a cost. So…