What more do you want?
And Gups it ain't just the sniper; guys react fire through obstacles any time. However at least the UI is different because you don't have the alien head symbol with crosshairs that represents 'visible through someone else'. It's a shame the iPad camera thing is so poor, because I'd have loved to make an hilarious video of all the times my sniper aimed and fired through a featureless wall. The last mission I did was UFO site, and by that point I'd given up on actually caring about the sniper's arc of fire, because he could shoot through it anyway.
Towards the end of the first terror mission I had a floater jetting about in a warehouse, who became visible every time he jumped for some reason. The building was intact and had no windows, a roof, etc. While I was moving my squad down the road toward him, my assault free react shot fired his shotgun through the concrete wall and killed the floater. This isn't 'can only see him a bit', this is shooting at a target nobody should be able to see through a giant obstacle. If he'd fired and damaged the wall or put decals on it or whatever, that'd be fine. He didn't, because beyond spotting calculations I don't think the game cares about terrain at all. He fired, the bullets went through a wall, the floater died.
On terms of what Vendetta is talking about, I once had a thin man shoot right through his own high cover and my guys high cover to hit me; he was a square off cover, so he looked and fired directly through it with no fudgey 'don't mind our shit LOS' idle animation. When I returned fire, the first shot spangled off the wall like a real video game. The second shot was fired in the drama camera at a 90 degree angle to the target, hit the target, and the targets corpse appeared on the near side of the wall he was previously behind.
Working as intended.
. Alternatively, the secret may be the height advantage - when getting the magical X-ray vision into a UFO my sniper usually has some height advantage.
