A group of randomly selected people saw a speaker giving a lecture on environmental ethics to a large and focused audience, and another group of randomly selected people saw the same speaker giving a lecture to a group of less audience less attentive in the same way
A group of randomly selected people may have a consistent understanding of the personal qualities of the speaker under a specific social environment
 The former group thinks the speaker deeply and confidently, while the latter group thinks the speaker's expression is vague and lengthy