I wonder if they’re all wired or run off batteries?

They may not be the same, but the ones we have in the EU, or at least the ones I’ve seen, run on batteries. They’re not connected to anything. You can just yoink one and it works. I’ve seen some people do that and was tempted to myself. Not sure about the software side. If it’s realistically possible to display something else entirely on them, then it’d be cool to have.