If we had to judge by the included diagrams, the trigger and bumper on each controller would act as the mouse click. Multiple included images show a hand with the thumb on the joystick. Multiple parts of the patent mention the use of the thumbstick, and we suspect it could act as the scroll wheel or serve some other scrolling function.

Interestingly, the patent also seems to conceive of a mouse mode for a more traditional controller. While the design of the device is rudimentary and still split in two like a Joy-Con, it is clearly one-half of a traditional gamepad with an optical sensor on the inside surface.