You are looking at a sawed-off cathedral. Or rather, what is left after a war and Communism meet a cathedral. The building “was damaged” by someone, the displays are careful not to say whom. Then it remained a shell until the DDR government blew up the remains, leaving the tower standing.
The model shows the before and the after.
What remains is a nice little museum about medieval church construction. There was no stone in the area, so all the churches and castles are made of brick. Brick Gothic is a major historical thing and you can take tours along the Brick Gothic route.
But religion was the opiate of the people, and the church is no more.