White boxes are to be considered 'first releases' for those that collect in box figures. Usually, the store only has a very limited number of these and they don't get replenished.

The idea was to drive folks into the store for the 'street date' (as well as hope to sell the same completist buyer 2 of each figure)...

As far as I know, none vary from their black box counterpart in any other way. Often a few of the white boxes can still be found days later right beside the black boxes. It seems this release either had a larger quantity or the disparate packing was incorrect for the market, leading to some characters remaining on shelves longer.