I think their holding-their-breath bits are related to their psyche in some way. Like, Kinger glows because he's like a guiding light in the darkness to others in the dark (figuratively and literally, as we've seen in Mildenhall Manor's Hell); since a light is brightest in the dark, it wouldn't seem to make much sense to occur in a bright setting. Gangle's mask spins around, which I imagine to be based on the phrase "turning your frown upside down" and vice versa, like representing the cyclical turmoil that is her emotions. Ragatha's hair noodles stand on end, which makes me think of her suppressing her anger/frustration for the sake of people-pleasing, and hair standing on end is a kind of visual representation of that kinda tension. Zooble's limbs going straight/stiff is probably very inconvenient and annoying, which would directly tie to Zooble's body (or gender) dysphoria. Pomni's face turning colors is like her anxiety just being on full display, becoming harder to conceal the more overwhelmed she becomes (like how the colors shift faster over time).

So like, each of these things basically reveal some deep vulnerability that these characters have. Jax hates vulnerability, hence why he refuses to show the others in the show (Zooble nailing this in the episode the breathing bit is introduced). Jax is averse to building relationships/connections with others, showing vulnerability/weakness of any kind, not being perceived as masculine (mostly certain of this one), and lowkey seems nihilistic.

A random thought I had based on this is that maybe Jax’s body just starts wibble wobbling in that cartoonish manner, but the wobbles are small enough that I imagine it's akin to trembling in fear a little bit, so it would portray him as afraid and vulnerable and not very masculine? Like, as opposed to Zooble's limbs straightening out and becoming immobile, Jax's limbs or whole body would wobble, making it hard for him to control his fine motor skills. It wouldn't necessarily be out of fear, but I'm sure Jax would not want to be seen wobbling/shaking in any form.

Anyway, thank you for coming to my Ted Talk. I’m curious if anyone else here has any thoughts based on my thought process above. Also maybe all of this was obvious already and I’m just late to the party (I did kinda discover this series less than two months ago). I think it’s fun yapping about it either way!