Subliminal perception is defined as receiving the influences without being aware of the existence of stimulus. This phenomenon is often observed when people are affected by a certain subject unconsciously when making decisions. If applied properly, subliminal perception could be used to adjust people’s thought without their knowing. In such cases, people often fail to be aware of the existence of the stimulus because it is either too short or too subtle to be noticeD、 Question: The professor uses one example to illustrate the definition of "subliminal perception".Explain how the example is related to the reading passage,