The ground handler/pushback operator will show the bypass pin to the pilots to make it clear that it has been removed.
What is by Aircraft Bypass Pins?
Aircraft Bypass Pins :
Aircraft bypass pins are used to bypass hydraulic system steering on aircraft, allowing for steering to be controlled completely by the pushback tug.

Once clearance is obtained from ATC , the pilot will communicate with the tractor driver to start the pushback. To communicate, a headset may be connected near the nose gear.Since the pilots cannot see what is behind the aircraft, steering is done by the pushback tractor driver and not by the pilots. Depending on the aircraft type and airline procedure, a bypass pin may be temporarily installed into the nose gear to disconnect it from the aircraft’s normal steering mechanism.

Once the pushback is completed, the towbar is disconnected, and any bypass pin removed. The ground handler will show the bypass pin to the pilots to make it clear that it has been removed. The pushback is then complete, and the aircraft can taxi forward under its own power.

NOTE
Failure to remove the pin from the aircraft will result in the pilot being unable to steer the aircraft from the flight deck.
Bypass Pin
Each bypass pin is made of high-strength steel and the kit comes with a bright red flag with the words “REMOVE BEFORE FLIGHT.” The flag is fitted to the pin with a heavy-duty clip and lanyard.
