This style illustrates a simple layout using using images within the table cell for the sidebar.
It could be argued that this style is just a subset of Style 2, using images instead of text links for the contents of the sidebar... that's ok. I'll document it in any case.
This style is often used on sites that are heavier users of images for text and for the look. The side bar may be a list or nested table that has a set of images, each linked to the desired destination or it could be one larger image that uses a map to define the link regions.
Yes, my graphic buttons for this example are extremely rough. Sorry, but it was a quickie... ;-) Of course you'd use something much more attractive, and would probaby use mouse-overs to give it some activity...