(Im)practical Joke

Last week, we (the Gazelle, Sporty, the Scholar and the Intern) had lunch at Pickwick's for a change. It was a nice change, too. I sat facing the very tall windows and suddenly noticed something...strange. Can you see it too?

It's a socket wayyyyy up by the window's arch. There were identically positioned sockets next to all the windows, in fact. I wonder what those power outlets you cannot possibly reach without a ladder are for. Fairy lights perhaps?