I dont know if it is possible to view the pics on the fly and have them auto save, but you can use the a switch (-a) to run it in adjunct mode then use (-d) for output directory e.g
driftnet -a -d /root/desktop/driftnetpics
you can of course ommit the switches just use driftnet and just right click on any intresting pics you see and save them.



(Driftnet Log)