From the Tango Gameworks blog today:
This is an illustration from someone the site refers to as "Mr O." Accompanying the illustration came the message "A random addition to the strange images of Mr. O. We’ll be periodically uploading some of his drawings, so brace yourself…"
You're going to have to guess who "Mr. O" is. So far, the known members of the Tango Gameworks staff is Shinji Mikami and Ikumi Nakamura. You can see profiles at the Tango staff page.
It's unclear if this has anything to do with Tango's upcoming totally unannounced games.