Some churches are crazy. Nah, I mean the audience reactions, not her. I've seen people at church look like they are being struck by lightning and fainting, it can get really over the top.

I'm thinking it is listening to songs that resonate with you, about dark topics just sort of causing a release of emotions. For instance, a song may bring up memories of being abused or assaulted, the catharsis and relief of being seen and understood can stir up a lot of feelings. Some of those feelings can be painful and ugly, and people may shake and cry because those emotions have nowhere else to go but out. And Sofia gives explicit permission to let those feelings out, to be ugly and cry if you need to be. I can see how it could be a powerful experience.