In this photo, I can see a sticker that has been scratched, underneath it is a code to remotely unregister. The code has been "blurred", but the scraps are visible. Normally there is such a silver surface. The visible code means in Germany, this car is not allowed to be driven without being registered with the authorities again.
What does this mean in Poland, what are the news of the officials, I do not know, I have been living in Germany longer.
But this additional stamp is redundant here according to the current regulations, the date stamp looks suspicious. The stamp of the office is not legible enough for me, check for yourself whether such a Zulassungsstelle exists at all and it matches the registration number (the first to a maximum of the third letters indicate the region where the vehicle was registered).
greetings
Cezary