There really isn't a whole lot, maybe 25%. BUT... there's an immersion instalation that puts you in the skin of a person in Guernica that day. You enter a room staged as a flat and a sound track telling the sorry of the woman living in it starts. She's in her kitchen etc. etc., and the, the bombing. Quite moving to me is the transparent floor which is laid on top of what would have been the floor of the flat after the bombing, with broken dishes, photographs, etc.
There are also photos, letters and other documents explaining the events that led to the bombing, why that city was chosen for the bombing (anti-Basque sentiment).
That's what I was expecting to see and was having to have seen, although the overall interest on peace as a more complex subject has its place as we look forward and not just back in history.