The Galaxy S4 Mini has many of its namesake's features in a smaller package.

Samsung has released a more compact version of its flagship Galaxy S4 smartphone. The S4 Mini has a petite 4.3-inch display (compared to its 5-inch predecessor) and an 8-megapixel rear camera (compared to the Galaxy S4's 13MP). Both devices run Android 4.2.2 and offer Samsung's built-in camera software features like Sound & Shot, Best Photo, HDR (High Dynamic Range), Panorama and Continuous Shot.

From Samsung's press release:

“We appreciate such unprecedented demands for the GALAXY S4 that we aimed to provide users with life companion for a fuller, richer and simpler life. And now, we want to give people more choices with GALAXY S4 mini, similar look & feel of GALAXY S4 for more compact and practical usages ,” said JK Shin, CEO and President of IT & Mobile Communication Division at Samsung Electronics. “The new GALAXY S4 mini provides consumers with a new way to enjoy the flagship GALAXY S4 experience.” 
With a 4.3” qHD Super AMOLED display, 107g light weight and compact design, the GALAXY S4 mini is easy to carry and operate with one hand. Though compact, the GALAXY S4 mini also boasts powerful performance, equipped with a 1.7GHz dual core processor that allows users to quickly and easily perform data intensive tasks. 
The GALAXY S4 mini supports many intuitive features and services provided by the GALAXY S4, designed enhance every facet of life.
Capture Important Moments
The GALAXY S4 mini allows users to capture important moments with an 8-megapixel rear-facing camera and 1.9-megapixel HD front-facing camera. Special features such as Sound&Shot, which uniquely stores sound and voice together as pictures are taken, and Panorama Shot, which allows users to photograph the full view of their surroundings, ensure no memory is lost. Receive travel assistance and information service through the preloaded S Travel application, which can also recommend future trips and provide a guide along the way. Users can also automatically arrange photos in a smart format with the Story Album function. Photos taken by GALAXY S4 mini are automatically gathered and saved according to the user’s timeline, geo-tagging information, or a specific event to create a photo album.