It refers to Supreme Court verdict by a bench headed by Chief Justice of India wherein while admitting Chief Justice being first amongst equals on one hand, exclusive right to Chief Justice is given to form benches on the other hand. Evidently by giving such a special right to Chief Justice without any fixed norms, Chief Justice gets some privileged right over his fellow judges thus negating the aspect of Chief Justice being first amongst the equals. Moreover it is against principle of natural justice that a bench headed by Chief Justice may decided about some aspect involving office of Chief Justice.
Seniority of judges is a well-established criterion in justice-delivery-system, and should not be ignored in practice. If such would not have been a reality, then collegium deciding appointments in higher judiciary could not compulsorily have senior-most judges as its members. But no argument holds good practically because Supreme court is final even though it may be wrong.