First, view the image down bellow.
Steps to duplicate:
1.Place down a Cobblestone Fence from left to right
2.Place down a Nether Fence to the right, just like in the picture. After that you will see that the Nether Fence has a weird possition, and it tries to kinda connect to the Cobblestone Wall.

Using iPad Mini 2, iOS 9.3.2 (latest), Minecraft PE 0.15.2