This sign caught my eye whilst I was in Boston’s North Station waiting for the train to my beloved home state of Maine last November. It’s a very large train station and there were several of these signs on the ceiling above.
While I’m betting that there’s a logical reason for it, I can’t think of any plausible explanation. Spiderman dropping by? Unlikely. Perhaps Lionel Richie or Fred Astaire, after all, it say’s do not walk on ceiling’; there’s no danger in a little dancing. 😀