This is what the 001 surface looks like from the top. The 2x1 reconstruction corresponds to the rectangular 2x1 surface unit cell. The surface layers need to be optimized to allow the surface atoms to relax, so that you will have some of the atoms closer to each other than in the original, unrelaxed structure, but VNL may not show the bonds because there is a cutoff value that is set for bond length in visualization settings.