Hello,
All these images are transparent PNGs from folder /images/demo/rotator. If you open any of them in Photoshop, you will see the upper part of the image (in example, above the character's head) is transparent.
You will need solid knowledge of Adobe Photoshop (or free alternative GIMP) to create such images. Also, these images could be non-transparent, but we used transparent images on our demo.
Regards
Milos