Can someone guide me what is the design pattern used in the below image?
What is it called?
It's called Cover Flow.
It's used by Apple in OS X (among others).
Cover Flow is an animated, three-dimensional graphical user interface element that is integrated within the Macintosh Finder and other Apple Inc. products for visually flipping through snapshots of documents, website bookmarks, album artwork, or photographs.
See: Cover Flow
As made clear by comments, Cover Flow is based on the Carousel pattern.
Carousels allow multiple pieces of content to occupy a single, coveted space. This may placate corporate infighting, but on large or small viewports, people often scroll past carousels. A static hero or integrating content in the UI may be better solutions. But if a carousel is your hero, good navigation and content can help make it effective.
More on carousels here.
Another interesting link provided via the comments about the origins of the Cover Flow here.
It's an ordinary Carousel with a fancy 3D touch to it.
Image source: Yahoo design pattern library
Carousels are often used on webpages, in this context a carousel often shows a single item at any given time and offers some sort of auto rotation function. Many think that using carousels on webpages (as header) is considered bad practice, for various reasons I will not cover in this answer.
Carousels come in may different variations and can be used in many different ways. An often seen usage is that of browsing a set of images (or albums) some offer a 3D like experience like in your example.
Navigation is often a combination of: scrolling, touch (mobile) or navigational buttons. When a carousel contains a limited amount of items a progress style navigation element can be used to show the currently selected/focused item (page-indicator).