The transmitted picture was taken with a camera onboard the space station looking out through one of the windows. NA1SS is the amateur radio callsign used by US astronauts while they are on the space station.
Richard Garriott has been very active on amateur radio ever since he arrived at the space station. Besides the SSTV activities he has been having voice contacts with schools and radio amateurs around the world. You can listen to Richard making voice contacts with radio amateurs in Europe in this recording.