The thin case edition of the demo came with retail issues of Official Xbox Magazine September 2003. It contains a video preview of Dino Crisis 3.
Subscriber issues of the magazine came with demos in sleeves. The discs are identical.
4. Front of sealed magazine with demo
5. Back of magazine
Thanks to eBay members bel_8780 (images 1-2), buenabae (image 3), and mac2collect (images 4-5).