The "non-standard" shape targets give me fits. If you look at most big game 3D standing targets, the body shape makes a rather standard rectangle shape that my mind processes well, making it eaier to pick a spot. The body is slightly wider than it is high but not by all that much. They just seem to look natural to me.
The low, wide rectangle body shapes like the lying down deer and the alligator just warp my mind as does the standing bear. To my mind, they just don't look right, and my brain keeps telling me this is a hard shot even though I logically know that if you pick a spot, it doesn't matter what shape the spot is attached to. Mind games, I guess. I won't even go into the way turkey targets trip me up.
A live Whitetail deer, the only big game animal I hunt, has that same natural, standard rectangle body shape, so I have no valid explanation as to why those shots cause me grief. Perhaps adrenalin figues into that equation more on live game.
Shooting through the trees and leaves doesn't make much difference. Its either I hit them or I don't. True, I hit them an awful lot, but that does not register as problematic. It's just an "oops" that happens.