There are four types of sensors — force, to measure pelvic floor muscle contractions; accelerometer and gyroscope, to track positioning and movement; and a temperature* sensor.
Force is the main sensor at play here — an orgasm is a rhythmic pattern of pelvic floor movements that occur during climax (1-2 hz if you want to get really nerdy about it). It’s basically going at a rate that is an involuntary body movement.
Accelerometer and gyroscope are for understanding positioning relative to what those pelvic floor muscles are doing. Right now they help give you cleaner data of your own body’s movements. There might be some fun things in store with these later, stay tuned. ;)
Temperature is for, well, measuring body temperature changes. Why? Because the vibrator will automatically start tracking a session when there’s a body temperature change. So if you turn it on and off many many times, it doesn’t capture all the other sessions, just the ones that are in actual use.
* Note that temperature here is NOT related to basal body temperature (BBT) for tracking fertility. That’s a specific process and purpose you can learn more about here from the Mayo Clinic. Do not use the Lioness temperature data for fertility purposes!