Don,
Come on man! 8 pallets and 20 LD3s are the same as 44 LD3s. Did you ever notice how cargo pallets are quite a bit larger than LD3 containers?
Boeing represents the cargo area this way to show customers that after loading all the passenger bags, there is still a lot of room, more than 50%, for palletized cargo.
Now imagine how many LD3s the A380 has to load and how much space is left over once that is done. Simply put, assuming full pax, the 77W has the potential to carry a lot more cargo.