This is based on a string in the app which reads, “Have your Assistant do multiple things with just one command. Use ready-made routines you adjust to fit your day, and create custom ones from scratch.” However it is unclear as to when the feature will be rolled out, but it does hint that it will be an upcoming feature.
For those who are learning about Routines for the first time, it is basically a combined set of commands that you can activate all at once. For example there is an existing routine for the morning when you wake up where you could get Google Assistant to turn on the thermostat, maybe get that pot of coffee brewing, read you the morning news, and so on.
However like we said, what’s available right now are presents which means that if you wanted to be able to better customize your routines, it will be a tad limited for now but as the APK teardown hints, customized routines could be in the cards in the future.