Am I visualizing/understanding atomic form factor correctly? I'm having difficulty visualizing the concept of atomic form factor or atomic scattering factor as it has been presented in a chemistry course on X-ray crystallography that I'm taking. At the moment, I visualize it as such:

(Please note that the question marks in the diagram above are included to communicate my confusion.)
Am I visualizing this correctly? Is there any other way for me to interpret these diagrams? The course doesn't dive into the mathematics of atomic form factor (and neither does our accompanying text), so I don't have much to go on in developing a mental image of the phenomenon at play here--and I strongly suspect that the mental image that I do have is wrong since I can't find any evidence to support it.
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.