What interests me about this picture is catching a glimpse of senators talking among themselves, not standing at a podium. Surely they're aware of the presence of photographers, though, so I don't know how candid the image is. Here's a PDF of the START treaty, and a story about current politicking around it.
Kevin Lamarque / Reuters
Democratic Senator John Kerry (R) speaks with Republican Senator Jon Kyl as they depart the Old Senate Chamber after a closed session about the new START treaty on Capitol Hill in Washington December 20, 2010. Between the two Senators is Carl Levin, Chairman of the Senate Armed Services Committee.