QUOTE
And that band to the right of Tethys? Is that also saturn?
No; I think it's another band of rings. The narrowing of the gap from top to bottom would come from viewing the rings at an angle, producing a series of (apparent) nested ellipses; close to the intersection with the minor axis of the ellipse the rings appear closer together, and as you move toward the major axis they seem to move apart; where there are gaps they appear wider.
However, there is something strange about this picture; in trying to determine just what part of the rings I was looking at, I tried to match up the image with a wide angle view of Saturn taken near Oct. 15, and I could not make the match. Also, for some reason, the image number (N00023152) isn't in sequence with other numbers for Oct. 15, which are in the N00021000-22000 range. N00023151 is an image of Titan from Oct. 23. I suspect that N00023152 has been mislabelled or misdated, or both.
N00023152 is listed in the index
http://saturn.jpl.nasa.gov/multimedia/imag...w/casJPGFullS04 and its date there is Oct. 25. (The Titan image with the preceding number is in a different folder, casJPGFullS05). I can't find any wide angle views of Saturn from Oct. 25, however.