Offizieller Kommentar
Using all-digital connections will provide the best quality of sound without loss of signal or introduction of noise through outside interference, but even for trained ears it can be difficult to detect on such short runs between the CDJ and the mixer.
I don't have specifications available on the DACs used in the products, but they're all very good quality and would have next to no audible difference in output.
The reason the videos differ depends on who's setting it up - sometimes it's done by an outside marketing company and they don't always know the best configuration, even if a Pioneer staff member is on hand during the filming.