The value of settling which parts of a pack are fixed is that the argument only has to happen once. After that a new capacity, a new model code or a new brand extension is a filling-in exercise rather than a redesign, and the compliance panel is never redrawn by hand.
It also changes what a retailer can say. Three boxes that share a service number, a warranty treatment and a handling panel are three products from one group. Three boxes that share nothing are three gambles.
The same logic runs through the digital side. Two sites, two jobs, one identity, so a customer who arrives from a pack, the film or a dealer lands somewhere that looks like the company they were just introduced to.