I'm confused how this is "new"?

Today I bought this (https://imgur.com/a/vreIc) copy of super Mario Galaxy 2 for Wii and didn't realize until I got home that the sticker says "new" but in no way is the game sealed and it doesn't have the manual or anything on the inside. I'm not really that bothered but I am curious as to where GameStop draws the line between "new" and "used". Thanks in advance