Just single material on a simple cube!
I implement many king of techniques for a depth-rich look, such as parallax effect.
It also includes a solution to prevent the rendering order issue on a two-sided translucent object.
The tutorial of this effect is here:
日本語 -> https://coloso.jp/products/vfxartist-heyyo-jp
English -> https://coloso.global/products/vfxartist-heyyo-us