ANALYZING THE PICTURE: Any?

A group of people interested in UFOs, in Maldonado, Uruguay, wanted to demonstrate how it is possible to perpetrate hoaxes with supposedly “ufo pictures”.

With that in mind, they hanged a top from a thin thread and took a digital picture.
When they looked at the picture in the computer they realized that there was something else that they didn’t see at the moment of taking the picture.
They would like to know what it could be.

I told them that my personal impression is that it is something either small or very high in the sky, most probably an airplane.

I made some work with the picture and I have it embossed, inverted, threshold, bas-relieved, etc.

But what is needed is an analysis of all of that.

Is any UAPSG member in conditions to make a good analysis?

Here is the picture and an enhancement of the interesting part of it.