I think the 2nd transaction they just confirm that you want to used the card on file, essentially linking your phone number to the card for transactions on thei

I think the 2nd transaction they just confirm that you want to used the card on file, essentially linking your phone number to the card for transactions on their products. They also redirect to web for CC entry the first time, I think they're using stripe to store it or equivalent. It's essentially sms-based interface. (from https://dirtylemon.com/ordering https://dirtylemon.com/ordering)