The Mamdani Administration staffer who prominently wore a keffiyeh in a slick video urging New Yorkers to go to the Rent Guidelines Board , may have sending a message with his symbolic attire, insiders told The Post. Mohamed Alharbi, the deputy borough director for Queens in the mayor’s Office of Mass Engagement, has not been spotted wearing a keffiyeh in public photos, interviews and videos, observers note. Colleagues were also surprised to see him in a keffiyeh, which many Jews equate with the Palestinian terror group Hamas. “I’ve never seen him wear a keffiyeh at work,” a City Hall staffer told The Post. Mohammed Alharbi is not known to wear a keffiyeh. NYC Mayor's Office/YouTube In a March podcast , the 28-year-old SUNY New Paltz grad who has described himself as an Arabic-speaking Muslim, is seen wearing a black blazer and crisp white shirt, sans keffiyeh.…