Posing trunks should cover the glutes completely, ala Zane. He was ripped, sliced and diced and he never showed his glutes.
Wasn't it a rule that you would punished somehow if you showed the glutes? Bodybuilding struggled for years to avoid the stigma that glutes gave. Then some fool, whoever it was, decided that "the glutes are a muscle like anything else and they need to be ripped." Whoever it was probably had poor proportions and balance etc and decided to go for balls to the wall conditioning to make his mark.
And the stupid judges fell for it.