The desk books Demo Guest onto a guest card valid until checkout, host: Front Desk.
The guest taps at the concierge phone. The Echo there says: "Demo Guest is here to see the Front Desk."
In the room, the guest taps their phone on the Wi-Fi card by the TV and joins with one tap. No app, iPhone included.
Housekeeping taps the sticker inside room 214's wardrobe door. The ledger records room 214, the phone and the time.
Checkout. The guest card expires. From the console it is ready for the next guest.