click anywhere on the desktop and then go to the menu bar > View > View Options and choose show icon preview.
See if that makes a difference.
Regarding the use of the word File. Your JPEG's are the file, the thing you create to put them in is called a Folder.
10.4.11 is the latest version of your operating system, use Software Update to bring your machine up to the latest.
Let us know about the icons
I have something that is driving me crazy. I have just upgraded to a Mac 10.4.9. When I download pictures, which are downloaded as Jpegs, I can see the actual picture as an icon on my desktop. However, when I create a file for any one of these jpgegs and move the pictures into the file. the picture disappears and it's replaced with an icon, which I have to click on to see the picture. I'd like to be able to pull up the file and see the pictures in icon form without having to click on the icon again. I've played around with it and can't figure out the solution. What have I overlooked or what do I need to do?