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

1. Modify the main body of the object to resemble a grooved rectangle. Currently, it is a larger rectangular body with two smaller rectangular extrusions. The overall shape needs to be simplified to a grooved rectangle.

2. Change the shape of the main body from a rectangle to a square. The length and width of the main body should be equal.

3. Ensure that the smaller rectangles attached to the main square have around 1/5th of the width of the square. The exact proportions are unclear from the images, so this needs to be confirmed and adjusted if necessary. The length of the smaller rectangles should remain the same as the square.