Sky Orb Goes Into "Blink" Mode?

Photo date: August 2, 2015. Photographer: Mark Mahin.

In the photo below, we see a mysterious orb floating next to a New York City school.

But the next photo taken a few seconds later from the same angle showed no such orb.

But then the next photo taken a few seconds later from the same angle showed what may be the same orb reappearing.

There was no fog, mist, rain, or precipitation on this night.  The air quality listed on airnow.gov was "good," with a rating of 39.