For the OP,
Try to find out which side of the plane will provide views of Table Mountain as you descend into Cape Town!! I flew from MUC to CPT on LH a few years ago and was on the right side-had amazing views of the coastline,city and Table Mountain.
But I don't know the route EK will take you coming from DXB and which side-left or right will be the best,assuming you arrive during the day? If after dark, it likely does not matter.