Hi Duff,
Good suggestion, but as 2+2 said, you loose the chance to rate the image, add tags, leave comments, and even view the image a little bigger so you can make sure that you want to download the image. There are sometimes where the thumbnail looks like something you want, but when you see it a little bigger there is something missing there... and then you decide you don't want it. I think that's the biggest reason why we don't do it that way.
The other option 2+2 suggested, I don't think it would work either, because sometimes people will wait until the image downloads and they can see it full size before the leave a comment, rate or tag, and if you automatically redirect back to the list, then you loose that chance also.
It is a hard decision, because I see where your approach would be helpful, and save people some time, and make the site faster, but I think we would be loosing an important aspect of the site by doing this.
If I can think of a good way to achieve this, we might do it, but right now, I think the way we have it setup is the best solution.
Thanks.