It does look like a balloon.
However, the Hornet is not hovering in space. It is clearly following the object at some non trivial speed. Even at stall, around 185MPH(155ish knots), you could never get a picture of it with your phone. By the time it got close, it’d be past.
So its moving a lot faster than a balloon.
And I guess it needs to be pretty large for them to see it and get a picture of it?
“However, the Hornet is not hovering in space. It is clearly following the object at some non trivial speed. Even at stall, around 185MPH(155ish knots), you could never get a picture of it with your phone. By the time it got close, it’d be past.”
You very well could be correct.
But, going by to my Dorito bag experience (post 14) that bag was whipped up by the wind, going quick fast at altitude.
It sucked along with me, quite close (meters away), due to the weird way air acts when an object flies through it at high speed. I thought it was far away and huge, but it was very close, and just moving back and forth a couple of meters.
The entire incident lasted seconds, but I suppose if I had a passenger, he could have gotten a photo.
The three pictures in the post are not sequential, they are the same picture with zoom settings changed.
The aircrew described the object as "motionless" in the text of the article. They were chasing nothing.