1 :- 3D layer or a Static layer option to choose image without mask
2 :- 4D layer chooser, when you click on this button you have to select depth mask and a static image of that mask. 4D image keep relation between depth and it’s image to show you 4D effect.
3 :- To control depth of your mask with image , click on this option and you will get a slider to adjust depth of mask. basically it control movement on the screen of that mask with respect to its image.
You can see a 4D text on the screen it shows that you are working on 4D wallpaper.it’s just an identifier.