Canadian government sources told a news agency that Chinese fighters have repeatedly intercepted Royal Canadian Air Force (RCAF) aircraft participating in a U.N.-sanctioned operation in international airspace. The Global News report, quoted in a Newsweek article, said, "Those jets are frequently flying as close as 20 to 100 feet from the Canadian plane," adding that Canadian pilots "sometimes see them raising their middle fingers."
Don’t know what the patches are for…but the “dent” in the wing is the inboard edge of the wing slat…goes in or out automatically, at slower speeds to provide more lift.