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

1. The object should be redesigned to resemble a workbench. This typically includes a flat surface for manual work.
2. The rectangle on the workbench should be made hollow.
3. The legs of the workbench should be centered and perpendicular to the upper surface.
4. A rod should be added that connects the bottom of the left and right leg. The diameter of this rod should be marginally less than the width of each leg. 
5. The proportions of the rectangle and the legs should be adjusted such that the length of the rectangle and each leg is approximately three times its width, and the depth of the surface is equal to the width of the rectangle.