Do
These are the things Kawa is allowed to carry out, and they are the only ones. Each goes down a channel the shops already use — the job queue a manager's panel writes to, or a script that already lives on the server. There is deliberately no box here that runs whatever is typed into it: this page answers on plain HTTP, and such a box would be a root shell on the internet with five tills behind it.
Restart a screen takes one screen down for a minute or two ← all
Switches an Android screen off and on again — the kitchen displays, the customer boards, the menu boards, the self-order kiosks. It is the thing to try when a screen has stopped answering the hub, or when adb keeps dropping half way through an install: a screen that has been up for weeks comes back and the next install goes through first time. Nothing is wiped and no setting changes. The screen is blank while it boots, so a kiosk somebody is ordering on loses that order.