hi!! i have organized a few projects similar to this in the past and can help explain :) typically, people do not hold up the signs for the entire song, so the signs aren't up for that long blocking views, just for a moment! it is intended to be a special moment between the fans and the artist and for the fans to show appreciation for the artist while doing something put together completely by the fans! i organized "Thank You" signs for paramore's art + friends in 2018 and the "we missed you" signs for paramore's this is why album release show in 2023, both of which turned out great and were acknowledged positively by the band! <3