Alice's breath is visible when she's outside in the cold, even though she's an android/SIM and shouldn't need to breath in the first place.
However, it has been established that she has been built to be very lifelike and this could easily include breathing. Also, breathing might be part of the SIM's 'metabolism', e.g. temperature control, or is simply needed for them to speak.
However, it has been established that she has been built to be very lifelike and this could easily include breathing. Also, breathing might be part of the SIM's 'metabolism', e.g. temperature control, or is simply needed for them to speak.