Easter egg? and suggestions

[Mitornimo]

This Game was amazing, when I get a chance I will review it. over all I would love to see future DLC's to this game, harder puzzles, and combinations of sins in one room, as well as more complicated puzzles (possibly In DLC) and maybe rooms with different endings based on paths you take, like checking the fridge first, instead of the couch might lead to a gluttony room ending... secondly I did some parkour in wrath, and found a message that states "whats inside the box" or something like that cause I cant remember... The question is, is that a easter egg. if so... what is in the box?