Direction of ferrofluid strands

Hi, I've heard that the nanoparticle strands orient themselves opposite/orthogonal to how iron filings would.
Iron filings align towards the poles, whereas the ferrofluid strands align around the poles.

Do the strands align in the same way as the visible lines of light? Or are these light lines the product of a kind of moire pattern effect?

I've seen a few videos of the strands being observed under a microscope, but to me this is not good proof one way or another. 
Does anyone know a definite way to prove that he strands align differently than iron filings?

Thanks!