With the launch of the iPhone 5 , Apple moved into a world of larger smartphone screens and embraced the potential of high-quality video playback. The internet device that was also an iPod was about to turn into a pocket cinema.

This is Day 15 of 30 Days of iPhone, a look at the moments that shaped the smartphone era .

Apple Goes Large With The iPhone 5 Redesign

Driving this was the display. The iPhone 5 was the first to move away from the 3.5-inch display that had been the iPhone standard since the first iPhone in 2007. The larger 4-inch screen had a 16:9 aspect ratio , all the better to consume multimedia content - three months after the smartphone was launched “Gangnam Style” would be the first YouTube video to reach one billion lifetime views.

Apple kept the iPhone width the same, so only the height changed when comparing the iPhone 4 and iPhone 4S. That let the UI accommodate a fifth row of icons on the home screen while keeping the ergonomics of the one-handed interface broadly intact. Crucially, it removed the need for letterboxing in most video playback.

Apple was not the first to bring a 16:9 ratio display to a mainstream phone; Samsung’s Galaxy Nexus and the Nokia N9 adopted this ratio for their 2011 launches. Because iOS hardware is closed, the community had to wait for Apple to decide whether its single smartphone design would accommodate video. With the iPhone 5, a more comfortable viewing experience had arrived.

The iPhone 5 Defined Displays For A Generation

With Apple joining the major Android manufactuers with a 16:9 aspect ratio, this rapidly became the industry standard. Displays would remain broadly this shape till 2021, as taller bezel-less displays offered more screen real estate while retaining a narrow chassis design. The redesign of the iPhone 5 was the keystone that helped define a generation of displays.

This is Day 15 of 30 Days of iPhone. Yesterday, we looked at iMessage and the stigma of the green bubbles .