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 been 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