Why do t2g set of orbitals have lower energy in octahedral coordination compunds, but its the opposite in tetrahedral compounds?

In Octahedral compounds ,Ligands are directed towards the axis . Since e_g orbitals i.e (d_x2-y2 and d_z2) are directed towards axis thus they face strong repulsion from ligands approaching towards them and hence their energy becomes higher than that of t_2g orbitals.Figure below shows how the ligands are approaching in case of octahedral.
In first image ligands approaching towards eg orbitals is shown.
In second image ligands approaching towards t_2g orbital(d_xy,d_yz,d_zx) is shown.


Now let us take a case of d orbital splitting in tetrahedral complex. In tetrahedral geometry when ligands approach towards d orbitals of central metal atom,they are directed more towards the t_2g set of orbitals that is d_xy,d_yz,d_zx as compared to that of eg orbitals.Figure below shows the position of ligands with respect to that of d orbitals of central metal atom.
first image shows the ligands approaching towards t_2g orbitals
second image shows the direction of ligands approaching with respect to e_g orbital.