It's meant to be 1 disc on the left hub and 2 discs on the right hub
It's the steelbook design that can hold up to 6 discs and is what is now used instead of jumbo steelbook
The hubs can stack 3 discs on each side on the new design and was introduced over a year ago with game of thrones one of the first releases to use the new stacking method
The deeper hubs is the difference