Is it prohibited to turn right in this situation even when it does not impede movement of other road users?

In the photo, behind the pedestrian crossing, there is a police officer directing traffic, facing you, with his arms held out horizontally to the sides. This position means that you must not enter the junction - and it applies to every direction, also to a right turn, even if you would not disturb anyone. The answer is: yes.

The Regulation on road signs and signals states that when the person directing traffic faces the approaching vehicles or has his back to them, this means that entering the junction is prohibited, and an arm held out horizontally across the direction of travel stresses this ban. Unlike the green filter arrow (S-2), the police officer's signal does not allow any conditional turn. You stop before the crossing and wait until the police officer turns his side towards you.

Legal basis: § 108 para. 3 and 5 of the Regulation on road signs and signals; Art. 5 para. 1 and 2 of the Road Traffic Act (Prawo o ruchu drogowym)