That is pretty cool picture. Interesting the ball appears black, silhouetted against the back ground.
I've watched with binocs at times when shooting #13 target at our range. It used to be a fox silhouette, but not changed to a large heart. Range is 92yards, iirc.
With the binocs, twice I have seen balls from a smoothbore arc towards the target, spot-on, only to veer to one side or the other, or dive into the snow seemingly in the last 3 or 4 feet of travel.
Of course that is an optical illusion, as they veered in the last few yards as they seemingly took on a spin. My thoughts are more powder, more yardage before taking on the spin - seems to work.
It is a remarkable sight to see. The fellow shooting these was using a 20 bore, with a .600" ball and 65gr. 2F powder. Watching Taylor's shot, with 85gr. of 2F powder, or Norm's shot with 85gr. 3F, the balls travel in a straight line, no dipping or curving out to the side. Those two rarely miss such a large target.
The ability or inability to see the balls in flight, depends a lot on the lighting. Some days, it's easy, while others not so much.