Ok, where exactly is it located then?
I hope you don't mean the OS X in the background, because that is not what I'm looking for. Take a look at the screenshot again, this is running in SmoothStripes, but the dialog still has stripes on it. So there must be a picture somewhere which has an cd and stripes on it, and which is only used in this dialog. The installer dialog are always stripeless. And to me it makes no sens that Disc Copy would get it images from Installer. I think it must be hidden somewhere in the System folder.