Its reaction with the odour molecules changes a detector's electrical resistance, and this signal is fed into a neural net (the closest that computer technology has got to imitating the pattern-recognising abilities of networks of nerve cells) to work out what is being smelt.
Then comes the work of screening scads of receptors against compounds to see which ones bind together--and what pattern of receptors get turned on by gardenias.
This case is a fine bit of regulatory work by FINRA. The AWC clearly sets forth the fact pattern, explains why the self-regulatory organization opted to go after the supervisor, and provides compelling rationale for the sanctions imposed.