Most importantly, the court found that the law was specifically and deliberately discriminatory:

Most damming, [sic] The appeals court — citing a lower court’s findings — noted that North Carolina legislators not only sought data breaking down voting practices by race, but then crated the law’s new provisions to single out practices disproportionately popular among African Americans, like early voting and provisional ballots.

This means that the court may place the state of North Carolina under the preclearance requirement of Section 3 of the 1965 Voting Rights Act.  (It was Section 4(b) that was ruled unconstitutional by the Supreme Court), because there was a finding of deliberate discrimination.