Facebook has rolled out an improved design for all iOS and Android devices. Photos are now 3x larger and posts in your News Feed will fill your mobile screen from edge to edge. This makes browsing Facebook on your iPhone much easier since you do not have to spend time waiting for individual photos to load.
The new Facebook design makes reading your News Feed easier, but they still left out the "share" button for iOS devices. It's also reminiscent of Instagram which Facebook acquired for $1 billion. The new larger photos ensure mobile Facebook users will browse their Facebook pages more rapidly instead of waiting for slow connection times.
Facebook announced the new design via the Facebook Mobile page, but I have yet to receive an update through my App Store icon. The announcement does say the new design will be rolled out today.