Should be light enough to move

In an article about americans working in middle eastern countries, cicy, a white journalist, is described as knowing that she should cover her hair when she leaves her house. according to this article, cicy:

Which function of nonverbal communication is at work? trey was planning a surprise party for lynn, but when she asked him why they couldn't go out on friday, trey shifted his eyes, coughed, and stuttered when he said he already had plans. what did trey's nonverbal communication do for lynn? clarify the relationship regulate the interaction increase persuasive power reveal discrepancies manage impressions

Which principle of design is in primary use in this structure?