You are looking at one of the two prototypes that the Carlsberg Group has created towards their goal of the world’s first “paper beer bottle”. The bottles are “made from sustainably-sourced wood fibres that is both 100% bio-based and fully recyclable.”
The difference is the polymer inside the bottle. Since these are tests, I (and probably they) may not know how the beer responds to heat, they are obviously shielded from light. Maybe we will all be drinking straight from fibre.