Hi Taerchen,
Check this link
http://www.macintouch.com/desktopdb.html for a discussion about the desktop file inclusion. Basically if you use Toast 4 (I don't have a newer version) in OS 9 (maybe earlier too?) to burn a CD by simply selecting the files off your HD then the CD contains a copy of the HD's desktop file. This may include information for files on your HD that you are not burning to the CD (you can check the desktop file contents using a program like Desktop DB Diver [freeware, thanks]). If you make an image first, then use the Toast feature (I don't have Toast on the machine I'm using right now so I can't check the exact command) that essentially burns the volume of that image to the CD then the desktop file only contains the volume information which is for the files that end up on the CD.
I'm working from memory here and it's been a month or two since I last burned a CD, but if I recall correctly you specify something like "make a new disk" to make a CD bootable. I'm not sure if this is exclusive of the volume burning option that you need to use with an image.
The main concern is if you have stuff in your get info "comments" (MSIE puts URLs there), or application information that you prefer not to share.