A new layout still includes cards but now they are expandable and you can also reorder or hide them. Some of the charts got an updated design as well.
The rest of the app looks pretty similar to what it was before but the bottom navigation bar got a new Workout tab. This section was located on the secondary nav bar on top of the home screen and now it has a new location.
Mi Fit - Apps on Google Play
The official app for Mi wearable devices
Source: @SaadhJawwadh