Each bar is wrapped in cellophane, which are then wrapped in the normal outer packaging. To make the 4 pack, they simply took 2x two packs and put them on a cardboard tray,and then wrapped those.
I don’t think I’ve ever gone through so much unwrapping for candy.
A single wrapper and the cardboard tray would suffice. You probably don’t even need the tray TBH. I don’t think I’ve ever gotten broken Twix bars, and I eat them all the time.