Ive been doing some digging into how digital-sstv works.
There are 2 transmission modes - normal and hybrid.. Normal is the usual picture transmission over the radio. Hybrid is a bit different and is the more common type of transmission. The sending station uploads pics to a ftp server and sends the url over the radio link, easypal then downloads the pic from the ftp service.
Cheating a bit I feel but it has to be said the pictures are so much better quality then the analogue sstv stuff! Some of the images Ive received on 7058khz in the last couple of days.