I investigated further and found out about the movie's straight-to-DVD status. Fast forward to San Jose, I decide to buy the movie (sometimes you have to) but the copy I bought had this DVD cover.
It also came complete with a slip case that simulates the motion of the zombie vomiting.
I knew something was amiss but didn't put together that this was not the same cover I had previously seen until I went to the Day of the Dead page on Amazon and found the movie advertised with this cover.
Further investigation unearthed this Kiwi version I found at the Day of the Dead Bad DVD Cover Art board.