Your adjustable steering wheel works by tilting either up or down as required, to allow the driver easier access and control over how they can see over the steering wheel. It was designed by Edward James Lobdell and used extensively by General Motors. It was something that was considered a luxury in cars it the 60’s. It works by releasing the ratchet joint which is on the steering column, and can then be adjusted either up or down as required. While the actual steering wheel moves up or down, it doesn’t change the length of it. Other types of adjustable steering wheels have been used to provide easier entrance and exit to the vehicle.
For more info, see How Does a Car Steering Wheel Work