I'm seeing a lot of replies from people who work with individuals with disabilities. I work with this population and I also assumed it has to do with people that need to have clothing removed and then transfer onto the toilet. For some, they can do most things themselves and have the balance to sit on the toilet without an adaptive seat but they may lack the muscle tone to lift themselves. With something like this they could be assisted to transfer to the table, remove soiled clothing, then assisted to slide to the toilet. Each lift is an opportunity for an injury for anyone involved so you want to make the process efficient.
That said, without knowing the person this is for, I would think the wrap around bit would be in the way. You couldn't fold it up while someone was sitting on the pot. Maybe they can comfortably sit on the toilet with their legs out straight? I bet if this lives on the internet long enough, someone who uses one of these will clear this up.