Hahaha, yeah.... I've been reading up stuff after this meme was posted... But yet any picture of a wall is pretty sensitive these days with the wall discussion being high, and not everybody is listening reason, and the picture also shows why that border wall will not work, or at least not as well, as intended.
When it comes to the line itself, I can say one golden rule of war (which also became once more clear when reading more about this). You cannot PLAN a war. As soon as the first bullet has been shot the plans need to be changed.
I guess the line itself worked as intended, but the flaw was there are always ways to bypass a barrier. It was an interesting read though, so thank you ;)