Sport Case Distinction?

Is there a cause why some Xbox One sport circumstances say “Xbox One” on the prime, whereas different solely say “Xbox”? My son observed the distinction and I haven’t seen any clarification. I’ve observed his copy of Bioshock The Assortment solely says Xbox on the header, the place as all of his different Xbox video games say Xbox One. Additionally, one the one which simply says “Xbox”, I observed that the Xbox brand is stark white and isn’t reflective like those who say “Xbox One”. Can somebody clear up this thriller for my child?