Orb looking object at high altitude, with bright flashing white light.

Thanks for taking the time to look into this. I was compelled to report this because of the unusual nature of the experience. This was seen on the roof of a residential building on 2nd Ave in East Village, Manhattan. The video shows a point of view looking at Queens/Brooklyn. The roof is about 15-16 floors in height. I was looking towards the east sky and noticed a bright flashing white light which appeared to be at a very high altitude and moving fast. The object was not moving like a typical airplane or helicopter. It appeared to be in the direction of and directly above LaGuardia airport. There were planes in the sky flying towards LaGuardia that are not shown in the pictures or videos because by the time I got my phone out to record they were out of view. The object moved looked like it was moving very fast and able to stop and stay stationary in the air at times, and it was emitting a flashing bright white light not familiar to me to be a typical aircraft. I have included a picture with a drawn red circle, where when you zoom in you can see the shape of this object. I could not tell if it was changing shape while in motion.