Magnetic fields, and lines, is what came to mind when I paid attention to this part of the fence while getting some sun in our yard.
I mean, if you think of all those images and videos about how the magnetic field of the Earth provides protection from the Sun's overwhelming power.
Of course, imagining things is easy in my current state... so I take things more metaphorically than I normally would.
So, let's make it a short post...
May your mind fill you with wondrous thoughts!