It depends if the content got votes within 24 hours. If it didn't get any (or many), then voting in the second window is essentially the same as voting in the first. So there is no loss of incentive to curate content that got missed in the first 24 hours.

The incentive does drop to pile on more votes on something already heavily voted in 24 hours. That may be good or bad, people probably have different views on this.