The story of these encounters is here.
The first photo showed a small shadow, as Caponi stated. The effect of the mysterious combustion of the two first pictures, altering the zone where the being was, resulted in this.
The first picture where the small being is clearly seen, at least as for the head, a hand, and some dark clothing on its back and whitish cover on its lower body.
The strange creature photographed in front of Caponi's workshop.
The second Polaroid of this day's encounter, with the being stead almost still.
The last picture of the being. Remember that Polaroid photos cannot be taken in fast succession.
Caponi made these drawing to explain the succession of events on the first encounter with the being.