Brent Lang Executive Editor of Film and MediaPoorna Jagannathan and Casey Thomas Brown are starring in Megan Griffiths’ “I’ll Show You Mine.”The dramedy, a Duplass Brothers Production, centers on Priya Sura, an author who has made a career of examining her own trauma, as she sits down to interview her nephew Nic for a new book about his history as a model who challenged gender norms and embraced his pansexuality in a very public forum.