Photoshop can do some amazing thing, but creating a 3D image out of something that is nothing more than a flat graphic or photo is pretty incredible. There's several different ways of doing this and smart photo editors know that each one has it's uses. To create a 3D shape you can use layers, postcards, 3D mesh, or you can create that “old school” 3D look with the red/blue image too – all from a single image in one program. That's impressive.
How to Make 3D Image
A postcard is an item that is an object with 3d properties that uses planes instead of 3d (for example a postcard, or menu since the images on these items are 2d even though the item itself is not).
Creating a 3D Mesh
smart photo editors know that this is the hardest to get right because you're in charge of the actual mesh. The layers method requires you to use one of their pre-made shapes but it's possible to make your own as well using this method. You'll need a grayscale image which you can make with any layer or picture.