Jeff wanted to explore this new ability further. It was clear to him how big of an advantage this was... seeing the top shelf, being able to position his head in hard to reach places without a body getting in the way... Just last week he wanted to look behind the fridge but his head was attached to his body and the countertop was in the way...
With just a few clicks he deactivated the transformation and was given options to favorite it for later use, reapply it to someone else, change how it is applied to him, reapply it with different reality settings... and upon selecting the reality options, the option to apply it to everyone appeared along with the ability to limit it to certain whatever's he wanted... genders, races, ages... he could even base it off of lima bean preference if he wanted to.
He could also choose how long its been a thing in the world. Since mankind could paint in caves, since now, since new years day of 2020. And what happens if heads and bodies mix... there's more detail to add there...
Eventually Jeff had it all typed up. Maybe opposable thumbs were the same way, maybe someone just decided to change reality so humans also had opposable thumbs and made it that way since the dawn of humanity... That seems less fun to explore.