If you want to read Hebrew or Arabic from left to right you can flip the book upside down but you will have to start reading from bottom to top
Someone told me they knew a salesman that could read upside down so when a client was reading a paper deecribing an item to buy they could read from the same sheet the client was reading and they said it was useful for sales
(Unsurprisingly, | is "flip horizontally")
A client might ask where is that thing to look at on my paper and without taking the paper away from them you can point ot out but you do not have to read upside down to be a salesman it is mainly about registering with the beast system paperwork to be allowed to sell whatever without going to prison and creating a monopoly by imprisoning competetors that did not register with the beast system
My immediate thought is "that doesn't seem like it'd be that useful, wouldn't you be providing the paper, so you'd just read it in advance anyway?", I guess this is why I will never be a salesman.