Sue Perkins presents the second Culture Show special from Edinburgh, featuring more highlights from the cultural event, like Opera de Lyon's production of Gershwin's Porgy and Bess. Alastair Sooke looks at the first UK solo exhibition of work by abstract expressionist painter Joan Mitchell, being held at the Royal Botanic Garden, Inverleith House, and there is comedy from the Fringe as Sue seeks advice from LA talk-show hosts Ronna and Beverly.