Interpret numpy.fft.fft2 output
You actually did a two dimensional Fourier transform there. The 0 Hz frequency is the ,,DC offset'' of your signal, that is, its average value. In computers, it's no wonder that there's a high average value, because signals are often defined using positive numbers.

In a 2D Fourier transform, the coefficients of the transformed correspond to products of 1D Fourier basis elements, that is, signals with a period equal to the length of the signal. You could call these overtones.

2D Products of two such signals are not ,,orientation agnostic''. In fact, they have obvious orientation along the edges of the signal. It is not entirely clear what you are asking for here.