Execute the "No scope" glitch twice and the game will be magnified 2x.
No scope
When you have a sniper rifle, press [Zoom] then quickly change weapons. Then, press [Zoom] five times. Note: You must do this before you fully switch to your secondary weapon.
Snowman
At the back of the second weapons room is a room with an angry looking snow man. You will also hear zombies in this room.