Does the "Stop" sign visible in the presented situation indicate the mandatory place to stop the vehicle before entering the intersection?

Why?

The B-20 stop sign visible on the right requires a stop, but its position does not mark the exact stopping point. Stop before the P-12 stop line if one is provided. If there is no stop line, stop before entering the priority road at a position where you can check that you will not obstruct its traffic.

§ 21 ust. 2 rozporządzenia w sprawie znaków i sygnałów drogowych