Tracey Ullman is back, this time on HBO, and she talks with Kurt Andersen about her new series and her hilarious impersonations of celebrities including Judi Dench and Angela Merkel. An artist finds a use for Hillary Clinton’s unused victory confetti. And author and YouTube phenom John Green talks about his new book “Turtles All The Way Down,” and how he treats mental health in his life — and in his work.