Buy a train ticket and immediately the train operator can see in real time how many fares have been bought as single journeys, or as returns at any point of time on any given day.
It appears the operator opted to maximize screen real estate while still keeping to the most compact size possible all in the name of customer convenience.
Some experts have commented that Angel Ambush was not 'real' augmented reality at all, because the virtual angel was just a layer of video manipulated by a human operator, rather than an independent 3D object.