I was intrigued by it actually being inside the exchange grounds.
Our posts crossed. This is one of those at a neighbouring exchange, which is is the BT car park and you can see its twin PCP on the pavement.
BlackSheep will probably recognise the exchange.
Last time I walked past and cut down the alley, it looked like they were putting another one in right up against the back of the exchange, was in a hurry at the time so didn't pay that much attention other than wonder where its twin was.