Image streaming is recording out loud the images in your minds eye. When you learn to decode the meaning of those images you can obtain a lot of ideas and insights from your own mind.
I've read a little about image streaming on the link you provided.I can relate to this as I tend to daydream a lot when I'm searching for answers or just philosophying.I do however have many questions about this technique so I'll read one of the books online when I have the time.Thanks for the link.