The motivation (if you need a reason) was to test the primitive driver motions and complete the full set of motions: waypoint, vector, primitive driver.
You enter the teleoperation/camera mode by going to the teleoperation mode GUI (F4), then pressing the start button below the keypad. Once started you can send the movement commands to operate. The keypad is not really a keypad at all but simply display the keys on the keyboard that affect the corresponding behavior. All the keys are mapped to what you would more or less expect. 'I' is forward, and the comma key ',' is backwards with "L' and 'J' being left and right respectively. It is more designed to be used on a laptop where you do not have arrow keys and the key arrangement is somwhat natural for controlling the vehicle.
Each key press simply adds an amount of wrench effort to that corresponding direction. This is accumulative, so if you press forward twice, you will have entered twice the wrench effort (twice as fast?). The Host GUI sends the wrench command (for instance L +=50; R +=50;)
The net result of accululation is sent to the target as final wrench effort via a service connection established. Thus, only the final wrench effort gets sent. Note, you should press stop when finished as it will continue to send wrench effort commands through the service connection potentially slowing down other commands.