The other dimension is a room in the snow forts that you are transported to during the phineas and ferb summer jam of April 2016 . In this room , Herb-Enshmirtz , the group Herbert and Doofenshmirtz created is already leader of CP . It will only be opened on the 20th day and closed on the last day of April. You are transported automatically.
if you throw a snowball in this room it becomes a Normbot
This is the only place where your puffle's EPF agent identity is revealed
If you transform into Norm in this room you become a Normbot