//Create a picture element and also set background and border symbology.
//Construct on the worker thread
await QueuedTask.Run(() =>
{
  //Build 2D envelope geometry
  Coordinate2D pic_ll = new Coordinate2D(6, 1);
  Coordinate2D pic_ur = new Coordinate2D(8, 2);
  Envelope env = EnvelopeBuilder.CreateEnvelope(pic_ll, pic_ur);
  //Create and add element to layout
  string picPath = @"C:\Temp\WhitePass.jpg";
  GraphicElement picElm = LayoutElementFactory.Instance.CreatePictureGraphicElement(layout, env, picPath);
  picElm.SetName("New Picture");
  //(Optionally) Modify the border and shadow 
  CIMGraphic picGra = picElm.GetGraphic();
  CIMPictureGraphic cimPicGra = picGra as CIMPictureGraphic;
  cimPicGra.Frame.BorderSymbol = new CIMSymbolReference();
  cimPicGra.Frame.BorderSymbol.Symbol = SymbolFactory.Instance.ConstructLineSymbol(ColorFactory.Instance.BlueRGB, 2.0, SimpleLineStyle.Solid);
  cimPicGra.Frame.ShadowSymbol = new CIMSymbolReference();
  cimPicGra.Frame.ShadowSymbol.Symbol = SymbolFactory.Instance.ConstructPolygonSymbol(ColorFactory.Instance.BlackRGB, SimpleFillStyle.Solid);
  //Update the element
  picElm.SetGraphic(picGra);
});