He's talking about the 3D Glasses icon (Switch Camera) next to the Smiley Face (Switch Game/Editor).
From what I understand, the Editor Camera allows you to pivot 360 and examine your area from all angles. The Game Camera will re-orient you to an angle that the player can see. So far I had no luck maneuvering around the area using Game Camera. I think it's more to help you add "secret" switches and stuff. If you double click a character or object in-game or on your list of characters/objects then you can zoom into them, activate the Game Camera and zoom in for a better look. This is probably the easiest way to get a realistic terrain-level angle using that cam. You can turn the camera slightly by holding down the middle mouse wheel then moving the mouse left and right.
However, so far it seems like the best way to explore your area is to use the Switch Game/Editor smiley icon to the left.
Last edited by JecklynHyde; 04/12/14 06:25 PM. Reason: added more info