It uses switchable glass, which contains liquid crystal molecules and an electric current to generate a smartphone display. There is no software running on the prototype as its main goal is to showcase the hardware.
Not all of the components are see-through as current technology doesn’t yet allow for transparent SIM cards, SD cards, or microphones. Polytron will be able to work around this by covering up the bottom section of the handset with an opaque filter where all of the non-transparent technology could be hidden.
You can take a look at Mobile Geeks’ hands-on video below: