Neutrality in the Public Square

In these public monument/display cases, the Court often points out that our Nation is a diverse and pluralistic one, and goes on to assert that the EC requires the public square to be neutral between religion and non-religion.

If we tried to construct a public square that was truly neutral in the sense that it was a reasonably accurate reflection of the diversity and religious pluralism of the relevant community (say, of Lincoln, Nebraska or Lancaster County), what would this neutral public square look like? Would it be strictly secular? Or what?