(TrendHunter.com) McDonald's is serving up its Oreo McFlurry treats in an immersive way thanks to a walk-thru billboard set up for a limited time on London's South Bank. Those who pass by the Builder'... (TrendHunter.com) McDonald's is serving up its Oreo McFlurry treats in an immersive way thanks to a walk-thru billboard set up for a limited time on London's South Bank. Those who pass by the Builder'...