The review courses are given with images, but they've been smart enough to not release the images (as far as I've seen) when they release recordings of the lectures or the PDF notes, so the advantage of paying and going to the course is to see the images they're talking about -- they know those audio/notes files get around, I would think. Some of the talks are pretty reliant on the images. Some you can still get 'some' useful information out of without them.