This photo is not a lens effect, and as this is a multiple witness case, what is on the image was probably in the sky. But what is it? It appears to be a cloud, so is it some sort of bizarre natural phenomenon? With so many weather anomalies these days, that seems possible. But could it also be something concealing itself in a self-generated cloud? Unless this is a very elaborate hoax, which in this day and time is always possible, it's a genuine unknown.