Exactly. Vending machines have never needed complex ways of detecting when a customer is ready to buy something, because there’s really no need for anything beyond having a button available for customers to communicate to the machine “I’d like to buy something”. What it sounds like to me is they’re using the facial recognition technology to track the demographics of who buys what and how often. Do men like X snack more than Y? Do women buy more in the morning or afternoon? Stuff like that.
Well, they did specify that the facial recognition software was there to activate the purchasing interface, rather than to advertise the machine’s contents, so I’m not inclined to cut them some slack if the real motivation was to show adverts to people when they’re claiming it needs to recognise faces because otherwise no one can purchase anything. (Why can’t the purchase interface be activated all the time, rather than requiring sight of a face? Do they think someone other than human beings is going to try to buy something? Is there a widespread problem with squirrels and pigeons buying from vending machines, which requires machines to know when it’s a person trying to buy something?)