Can you help me turn an Android phone into a computer?

My friend needs to use his phone in computer-like ways while he’s at work. He works at a hospital, and they will not allow him to bring a tablet into work.

He has a Samsung Galaxy S7 Edge. He needs to attach an external monitor, keyboard, and mouse. He can easily attach a Bluetooth keyboard and mouse, but what can he do for a monitor?

Any ideas are greatly appreciated.