Havent used it yet, but we were notified last week by reception at Santa Fe that it works with your room key card, like a regular contactless bank card.
We only walked by it, but it's a coffee machine, like you would have at work, also has tea and hot chocolate etc. And I think it's instead of using your bank card to pay, you use your room key card. At Santa Fe it was one free drink a day.
I was at DLP in September, I think it was 1 drink per person per day. I was told that if my buildings machine was out I could use it at any other building, so I'd assume you could use it at any hotel property as well
I think it's relatively new. I didn't hear anything about it during my stay mid September or my stays before. Last visit was the first time I heard about it.