How do I achieve a crust like this fried chicken?
I do not know about the chicken in the photo, it appears certainly crunchy, but not very appealing to me... 
anyway, the first dredging you do in buttermilk is useless: normally you have three phases for perfectly breading food for frying: 


dredging in flour (wheat flour, starch or anything else, even a mixture of flour and powdered spices that also make the meat tastier) is important because it "dries" the chicken surface and consent a better coating of the liquid;
dip in a sticky liquid to coat:  the support for the crunchy finish. can be buttermilk, beaten eggs, milk... the denser the liquid the thicker the coating
the "breading", that can be made of flour, breadcrumbs, sesame seeds, natural rolled oat, crushed cornflakes...


For juicier meat is better to marinate or brine it the night before
for crispiness the frying temperature must be controlled and well kept at around 165°C