This is booking the appointment for you and Google shows that Google Assistant has made a phone call. In his Google I / O 2018 he showed how Google Assistant can make phone calls for you.
image video source - https://www.sunnyskyz.com/happy-videos/7203/Google-Demonstrates-039-Google-Assistant-039-Making-A-Phone-Call-And-Booking-An-Appointment-For-You
It's incredibly realistic. In this demonstration he is booking hair salon appointment for a woman named Lisa. The fact is that they used 'umma' and 'ummhmma' in the conversation.
