Answer:
The number of likes a post receives increases the perception of credibility that people have of a social media post. As said, in the article, "if other people have liked a post, new viewers will be more likely to like it too." (Paragraph 20) This is why we need to "pay careful attention to what [we] like, share, or comment on" because our "actions influence what other people see and hear in the media." (Paragraph 21)