Just a couple of ideas
Are you sure that the CD is good? Can you view it on a windoze machine?
Sounds to me like the CD is not getting mounted. You can try to mount the CD manually as root. If it has a file system on it.
Stick the CD in the drive and issue
Scroll down to find out which drive the CD is if you are in doubt. Looks like /dev/hdc
The Details say it is write protected
Try to mount it read only.
Also was it a multi session CD? You may have to mount the session that the pictures are on.
If it's a drive access permission problem then open your picture viewer as root and try to access the drive.
A little more info on what wrote the CD would be helpful. What kind of file system was put onto the CD. Or no file system, but requires a particular application to access it.
Also was it burned with just joliet and not rock ridge extensions? Or is it a picture CD with no file system? Your going to have to find out what you have.