As I stood before the magnificent tapestries and tapestry cartoons (full sized drawings made in preparation for weaving) on display in “Once Upon a Tapestry: Woven Tales of Helen and Dido” at the Norton Simon Museum in Pasadena (on view until May 27, 2019) I wondered if during the Middle Ages persons of means looked at the woven narratives unfolding serially across larger wall hangings as we do movies, TV and our smartphones â as entertainments, as chronicles of human foibles and for the mora…