In chapter 3 (bank), how do the pictures lead to the code (4132) to unlock the box?

Chapter 3 is the Church.

You will find a locked box with a clue underneath. This shows 4 shapes (rectangles) in order.

On the wall of the back room are 4 pictures of matching size and shape. Each picture has a number of lines. Count the lines and put them in the order shown by the clue.

If you need any more help check the guide for chapter 3.