Lewd comedic picture of magic spell going wrong.
Coloring of earlier posted sketch.
Most of magic props and detachment artifacts are created to safely detach and reattach body parts, but not necessarily for swaps. While lots of enchantments allows swaps and even rearrangements; in case of different body shapes or sizes using blades, belts or even common sawing boxes leaves odd looking seams. Which is fine on a magic show, but sucks when you want to borrow friend's asset.
When it comes to more swap-oriented props and artifacts, most common ones focus on heads or faces.
So what to do when you wanna borrow roomie's thicc and smooth lower parts for a date? There's nothing you can't do with good old magic spells, right...? Well, Sam and Sandra despite being magicians, are not really good at magic when it comes to something more advanced than simple detachment or going trough a solid wall. Sam found transformation based swap spell, but girls messed it up and instead of lowehalf-lowerhalf swap they've got lowerhalf-upperhalf.