Can you change the price?
From the article photo, it looks like the 'pump' is actually some sort of monitoring device used to track how much gas/diesel is in the storage tanks. I imagine that gets used by suppliers to anticipate delivery requirements.
I don't know if the same system is used to control the pricing at the customer pumps, and the article doesn't make it clear. I'd guess than since this was published there are going to be some who will be trying it out though.
Depends on the monitoring device. Some of the monitoring devices connect to both the pumps and the tanks so that you can compare how much gas was pumped vs how much gas is left in the tank. Although it is not 100% accurate, if there are leaks or pumps that are way out of calibration, the device might be the first indication that there is a problem. And yes, the major use is to track how many times a tanker needs to come by and fill up the storage tanks.
On systems with Pay-at-the-Pump that take credit/debit cards, the same device connects the pumps to the authorization systems. Sometimes this is over a phone line, but some deal with satellite or internet connection to the authorization centers. These monitoring devices have a lot more control over what is displayed at the pump, and sometimes you can change pricing through the device. The ones that have this kind of control are *supposed* to have better security, but having to type a pin or password each time you connect to it is "really inconvenient."