Try something like:
Show All Records
Go to Record [ First ]
Set Variable [ $filePath ; Case ( Abs ( Get (SystemPlatform) ) = 1 ; "filemac:" ; "filewin:" ) & Get (DesktopPath) & "ExportFolder/" & YourTable::SerialID & ".jpg" ]
Export Field Contents [ YourTable::ContainerField ; “$filePath” ]
Go to Record [ Next ; Exit after last ]
This will export the pictures to a folder named "ExportFolder" on your desktop (the folder must be created beforehand).