I'm running Windows Phone 8.1 on a Nokia Lumia 920, and can have four quick actions in Action Center.
However, I've seen pictures online that show Action Center with five quick actions. For example:
How can I have this on my phone? Is there a setting I need to enable (like the "Show more Tiles" option that adds an extra column of tiles on the Start screen)? Or is it tied to some hardware capabilities like screen resolution or size?