Except to a layman it is basically magic. Using X technology we did Y so you can do Z. I'm sure in coming months you'll get the in depth technical explanation you are looking for but this announcement isn't for you it's for the average person.
That's a rather defeatist attitude to have about explaining technology to laymen.
For example (not saying this is how it actually works): "Scanning your phone when you enter lets us know who you are. Then, our advanced vision tracking system follows you around the store and lets us see what you're choosing. Finally, scanners in our turnstiles verify your purchases as you're leaving the store."
