Based on the answers provided, the following corrections need to be made to the 3D object:

1. Change the shape of the object to resemble a pillar. This could mean making it cylindrical or square in structure, rather than a long, thin bar with a rectangular cross-section.
2. Modify the base of the object to be square-shaped instead of rectangular.
3. Include a smaller rectangle in the design and ensure it is centered at the same location as the square base.
4. Ensure that the length of the smaller rectangle is the same as the side of the square base.
5. Adjust the width of the smaller rectangle to be around half the width of the square base.