The paying method you mentioned is implemented several years in Lund university in Sweden.
And today in China, Alipay is supporting to use your face without taking the mobile to pay if you set the permission.
One step closer to complete surveillance over who pays for what. Once the government can monitor every payment being made they'll be able to sell that data to corporations. It'll be every economist's wet dream.
This face transaction business is a bit worrying to me. I don't think I would support that myself. It's like the chip implementation or fingerprint reading system that they've got in mind for cardless transactions. The problem is many countries are still resistant to the concept of not having cash in their pockets.
For me, I recommend bitcoin will be the best payment medium method in terms of paying bills because it is convenient to purchase in any particular products without stepping out to your house. I think it is the best opportunity that the government of the country should begin to study the perks of getting bitcoin to involve in the industry.