What makes "Do Androids Dream of Electric Sheep" a postmodern text?
I would argue that three things combine to make Dick's fun book postmodern.
First, the slippage between the real and the virtual. This is an essential element of postmodernism for some theorists.
Second, the role of technology. This isn't as central to postmodernism, but does define some texts.
Third, the flattened emotional affect of the characters and the entire text.