The halides of transition elements become more covalent with increasing oxidation state of the metal. Why?

This problem is based on the concept of Fajans’ rule. As the oxidation state increases, size of the ion of transition element decreases. As per Fajans’ rule, when the size of metal ion decreases, covalent character of the bond formed increases.
Therefore, the halide of transition elements become more covalent with increasing oxidation state of the metal.