don't understand the scale portion

[brealisty]

im_patch_scale = getScaleSubwindow(im, pos, base_target_sz, scale_factor*scale_factors, scale_window, scale_model_sz, p.hog_scale_cell_size); xsf = fft(im_patch_scale,[],2);

why the 33 scales multiply the scale_window(33 length) respectively?

fft(X, [], 2), the arg '2' it means fft by row, but we konw each column of 'im_patch_scale' is a scale. so, why don't set the arg '1' to fft by column for a scale image?