What about monitors with screens on both sides?

Remember last time when you were buying a ticket to the movie and the sales lady had to turn her monitor to you so that you could see which seats shes talking about? or when you were trying to get your head between bus ticket salesman and his monitor to see in which part of the bus is the seat located he is talking about? Well, why dont we have monitors with screens on both sides? Remember those flip phones that had an additional smaller screen on the out side of the phone so that you dont have to open your phone to see time or if u've got any messages or misscalls? Why cant have we that type of monitors? the main screen will be used by the person operating the computer, (i.e. salesman) who could decide what to show to the customer and what not to. The custumer needs to see location of his seat in the bus / movie, be able to see options of payments/installments in the tour agency where he is buying a tour, etc. That's it, the salesperson can choose to show customers the window a customer needs but may choose not to show a window where she was playing game before the customer came, because she was bored. It can be a 12'' display on the back of 19'' display, and may be on even lower resolution. I dont need 1280x1024 resolution to see the location of my seat, I would prefer to be able to look and see a tour details a smaller screen with lower resolution while the salesperson searches for alternatives rather than making her rotate her screen to me every time she things she found a tour that fits my needs.