A poster shows the same thing everywhere. A web page does not have to. Screenly can tell a page which screen it is loading on, by sending details about the device along with the request: the screen’s name, and other context about it.
A page that reads those details can adapt itself. One dashboard URL shows the New York floor’s numbers in New York and the Chicago floor’s in Chicago. One room-booking page shows each room its own schedule. You publish a single page, and each screen receives the version that is right for it.
This is the mechanism behind an idea from Content: manage one piece, show many. Instead of building and maintaining near-identical pages for every location, you keep one that knows how to localize itself from what the screen tells it.