When I decided to replace these photos with scans, I must admit that my curiosity got the better of me. This promo was still sealed when I first got it, and since the promo sticker was always missing from the front, I wondered a bit about the CD. So I decided to slice open the packaging. I normally don't do that if something is still sealed, but in this case I didn't see it as a big deal.
There are some very specific differences between the promo and the normal release of King of the Mountain. You can also take a look at the normal release here to compare.
The general release is slightly taller in height and thicker in width to compensate for the secondary insert, which the promo does not have. The colours on both releases also vary - the promo has darker colours and the general release has lighter colours. On the back of the promo the lyrics for King of the Mountain are printed, but on the general release these are printed on the inner insert. The general release also has a large barcode on the back, which isn't present on the promo.