A memorial needs to be visually impactful to get the visitors attention.  It doesn’t need to be colorful or pretty, a half opened door or other device can draw the viewer.  It needs to be informative.  The more you can say without words, the better.  It needs to be personal.  The color action shots of the victims doing every day activities made them seem more like you and ms, more deserving of being remembered. The memorials need to be frequent to keep the memory alive.  The memorials done by their friends at local businesses dramatically add to the state sponsored ones to keep the atrocities from being forgotten.