I think the whole idea here is to show off exactly how the skeletons don't fit inside them, because anime people doesn't exactly conform to proper anatomy. I mean hell, look at the middle girl's eyes as compared to her eye sockets, how would that even work?
I mean, I don't want to like... discredit whoever did this skeleton thing, but the actual skeleton on the girl on the right doesn't look quite right. Anime isn't about perfect proportions or anything, but wouldn't that arm bone thing go down to her knee if it were extended?