Strange UFO snapped over Brooklyn, New York

On August 29, 2015, in daylight, a man nicknamed Alex has photographed a luminous UFO flying over the borough of Brooklyn (in New-York). What is it?

Witness statement:

I noticed a bright star-like object in the sky in daylight that gave off a flashing / pulsating phenomena of bright colors. I was only able to see the object for about 7-10 seconds until it disappeared. For reference, the object was about 30,000-40,000 feet in the air.

I attached 4 images of the same object: 2 original, and 2 zoomed in versions. I tried to take a 3rd picture of the object, but it vanished. I took these photos on a Samsung Galaxy 21x zoom.

If you could please help explain what object this is, I would very much appreciate it.