This identifies, by an enumerated name, which specific FSM workflow definition is currently driving this Image object's processing -- for example the standard validate-and-register sequence. This tells an admin which exact workflow type this particular image is running through, which matters because a deletion workflow versus a normal validation workflow would explain very different current behavior for the same image. A value such as 'Local' here identifies the standard local-validation workflow for this image, as opposed to a remove/cleanup workflow that would run if the image were being deleted instead.