I did think it was weird because the light paper style was what your images showed, but inside the demo itself, everything past choosing your pronouns and the little text that said 'let your journey begin' was dark text on a dark transparent background. The only thing that was paper style on my screen were the small notifications after a choice that said +bravery.
Additionally, I couldn't see the choice at all. It was just a black screen but when I clicked blindly, I could see an option being highlighted and there was some white text I didn't have time to read before it went to the next screen (because I had 'chosen' already). I'm playing on mobile browser by the way!