They showed the two stills of the picture in question and it was so blurry I couldn’t see any detail at all - so I question its value. Perhaps the state wants to just plant a seed of doubt into the jurors minds, but overall it seems silly.
The whole issue of the individual frames grabbed from video to show that during a single frame, Kyle's rifle was for a tiny fraction of a second pointed in the general direction of Ziminski (who was armed) seems bizarre.