Continued from yesterday.  Alastair John Gordon’s newest exhibit, “Souvenirs from the Waste Land,” draws on the postcard collection of Howard and Roberta Ahmanson, philanthropists and art collectors in L.A. Their collection includes mementos from their travels, scenes of architectural interest, and reproductions of works of art—over 18,500 postcards in all. I spoke with Gordon by…

  Historically, modern art has prized originality and authenticity. But alongside this tradition runs another set of practices: replication and tactics of illusion. The Romans made copies of Greek sculptures; Northern Europeans in the seventeenth century practiced an illusionistic approach to still life painting called quodlibet, or “what you will”; American pop art reproduced images…