In my testing I've found that mine has a bit less extreme effect on the face and does not affect body movement, specifically it doesn't add much breast jiggle. There aren't triggers necessarily, but you can control her head movement in particular with your prompt. Head back: She is orgasming. She is experiencing an orgasm. As she orgasms, she throws her head back and opens her mouth as she moans loudly. Head less back (in my testing it doesn't lead to much body shaking, but does keep her head a bit straighter): She is orgasming. She is experiencing an orgasm. She closes her eyes and has a screaming orgasm. Her whole body shakes and spasms as she has a shaking orgasm.