Based on the answers provided, the primary correction needed for the 3D object is to ensure that it is primarily a large square. Currently, the object appears to be a combination of a square and a right triangle, which is not uniformly square. Therefore, the model should be adjusted to remove the triangular aspect and ensure the object is primarily a large square. The extrusion and the right triangle cutout from the bottom-right corner of the square are correct and should remain unchanged.