Am I visualizing/understanding atomic form factor correctly?
In your illustration, there seems to be a little «almost step».  But more importantly, if displaying a heavy scatterer (iron, Fe) next to a weaker one (C), you should put a bit more emphasis on the descent for iron.  This is one of the reasons why the atomic position of the heavier atoms are easier to attribute in the Fourier map, than the lighter ones.
Take a look at IUCr's illustration from their freely accessible on-line dictionary:

(credit)
Maybe your school has the printed or / and electronic version of the IT (the International Tables of Crystallography) which goes into further detail (e.g., listing $f$ and $f'$ for the elements, obviously dependent on the wavelength of radiation used during the diffraction experiment).
Because currently many schools' libraries may restrict access and borrow the books in person, note that IUCr moderates a dedicated section of teaching pamphlets, too.  Topics include e.g., crystal packing and symmetry.