They're clapping and cheering when indicated to, and at the end of songs or solos. And naturally no audience on the planet except for Jacob Collier possibly claps in time, that too with time signature changes and syncopation like Polyphia
They could learn alot about stage presence from a band like The Warning. Once the Warning saw how being statuesque was keeping the audience distant, the worked on moving and engaging their audience. Both benefited
The playing is extremely technical. They've openly talked about it, basically every song in their discography is fucked to pull off live. I think we can cut them some slack.
Japanese people have a culture of concentrating on appreciation rather than making a fuss at a concert. They want to hear only the sound that the artist makes, not the noisy voice of the person next to them. Of course, this has both good and bad sides.
I know it looks kinda lame on the video but I was in the front I can assure you we were more than hyped up, every time a song or a solo started we cheered like crazy, my voice was completely gone after the concert too haha
jap audiences are quiet and respectful - opting to enjoy the music itself than to disrupt it. Alot of musicians feel their actual work is better appreciated there.
Japanese concert cultures a bit like this. They are more quiet and not as heavy movements as to not disturb other people’s experiences. Not every japanese concert is like this but majority are.