What wall materials to use behind glass shower wall?
They are gluing it to a form of drywall in the video.  I am not sure what the choices are from the manufacturer but I will make two comments.

Glass panels are probably hung the same way as big mirrors.   Preferred on drywall and glued.   Why drywall?   It has a little bend in it.   Glass/mirrors have play too.   For instance you would think gluing mirrors on plywood or concrete board would be more secure or easier.   Nothing further from the truth.

Love this system.   Glass/Tile-like paneling will be the wave of the future.   The maintenance levels, longevity, water-proofing... this is where it is at.   I have installed some granite sheet showers.   They are great but granite is porous.  This one-ups the granite sheets.   Also these can carefully be taken out if there is an issue.


Coolest shower I have seen in my life was pure glass panels.   The inside of the walls were painted 3 different colors and it was a work of art - used antique plumbing lines.