Umberto, thank you for replying. But IMHO, it doesn't make sense.
This is what's happening:
Captain: We have a good engine start, you can disconnect.
Wingwalker (or push-back operator?): Unlocking gear.
Push-back truck drives back, Wingwalker walks out of sight, probably to a position under the aircraft.
Wingwalker: Tow truck disconnected, bypass-pin removed, left is clear, right is clear.
Wingwalker comes in sight again and walks to a position in front of the aircraft.
Raises his right hand and subsequently raises his right hand again in combination with moving his left underarm to his left leg.
Text: Have a good trip.
Wing walker walks to the push-back truck, embarks it and the push-back truck leaves the scene.
So, when the wingwalker makes his arm signals, he has already said that the bypass-pin has been removed and that left is clear and right is clear. It doesn't make sense to repeat that from another position with arm signals.
This is what the manual says about these arm signals. This signal provides an indication by a person positioned at the aircraft wing tip to the pilot / marshaller / push-back operator that the aircraft movement on/off a parking position would be unobstructed.
So, the manual doesn't mention the removement of the bypass-pin, but does mention left is clear and right is clear. IMHO, this is done twice. Once by voice under the aircraft and once by arm signals in front of the aircraft. The manual also speaks about a position near the wing tip, but actually the position is not near the wing tip, but in front of the aircraft.
Speaking about the wingwalker. When still at the gate, the wingwalker disembarks from the push-back truck and teleports himself to a position under the aircraft. After that he teleports himself back to the pushback truck and lifts with the push-back truck towards the aircraft.
Another strange thing happens when the wingwalker walks toward the push-back truck after the arm signals. He walks right through the push-back truck before embarking the push-back truck.
To me, it seems that this whole procedure needs some improvement.
Hans Hartvelt
The Netherlands