The Lock Screen has changed in iOS 10.
In iOS 9, swiping across a reminder notification from right to left reveals up to two Interactive Notification actions. By default, they allow you to postpone your reminder, or mark it complete.
In iOS 10, depending on the device that you use, the same swiping action now displays either View and Clear on non-3D Touch devices, or just Clear on 3D Touch devices.
To access the Interactive Notification actions, you'll need to follow the steps below, depending on the device that you use.
Non-3D Touch Devices (e.g. iPhone 5, 5s, SE, 6, 6s)
Swipe from right to left across the notification. Tap on the View button to reveal the notification actions.
3D Touch Devices (e.g. iPhone 6s, 7)
Press firmly (i.e. 3D Touch) on the notification to reveal the notification actions.