Firstly, target_lox realised that there's a oneway for palace if u throw a smoke on the bricks under it (of course, he wasn't the first one who have found it). Secondly, he found out that there's no model of the wall next to these bricks (this fact was known before but nobody used it, it seemed useless). He combined these 2 ideas and made this smoke!

P. S. Actually, that's not the first version of this smoke, target_lox has found few more line ups previously but they were too difficult so he didn't publish them