Another Blue Orb With a Curved Stripe

The photos below all show a similar structure at Grand Central Terminal, a decorative structure above a window.  I took the top photo on October 11, 2016.  The other two photos (reported here) were taken on October 3, 2016 and September 12, 2016.  Three orbs at about the same position, all blue, and all with a curved stripe. What are the odds against such a thing coincidentally happening?