I think that there are some distinct ways in which the setting accentuates and helps the reader to visualize the intense conflict between both women. The terrace that overlooks the Colosseum and Forum allows both to see the ruins that exist. The structures and monuments, once the pinnacle of human achievement, have now devolved into ruins with only gutted shells remaining. This helps the reader to visualize the conflict between both women for as the afternoon goes on, all that is left between the women are the ruins of their friendship. At one point in time, these women were friends to one another. Yet, after the discussion between them, like the Colosseum and the Forum, there are only ruins. The vestiges of what once was is a reminder of what used to be. This is how the setting helps to envision the conflict between both women and its results.
Another way that the setting helps the reader to visualize the conflict between both women is that Rome, itself, is an embodiment of aggression. The Colisseum was where gladiators fought to the death. The Forum was the emodiment of Roman government, where decisions to conquer others were made. Both realms, now in ruins, represent the reality of conflict and rivalry, domains in which Rome's thirst for conquest was defined for generations. In this light, the setting helps the reader to visualize how this rivalry becomes an embodiment for the emotional rivalry of the two women. Like gladiators who fight to the end, both women seek to hurt one another, exchanging thrusts with one another until Mrs. Ansley's decisive blow. In such an exchange, the backdrop of where the women are in Rome helps the reader to visualize the intensity even more.
Oh, What useful ideas! Thankyou verymuch.