How should I explain my desired results for a bbl? (photos)

Far more important than the technique is the skill and experience of your plastic surgeon. Choose your surgeon rather than the technique and let them explain why one technique may be better than another. See the below link on some suggestions on finding the most qualified Plastic Surgeon for a BBL Always insist on a board certified plastic surgeon.

Based on your photo you appear to have a classic square shaped buttock which can be transformed into a round buttock shape with an improved waist-to-hip ratio. You appear to be good candidate for this type of reshaping. An exam in person with an experienced plastic surgeon will give you more information.Your height is irrelevant.Best wishes,Dr.Bruno

Hi Heidi,
Great question!  Apps are great to give us a sense of what our goals are.  What you are asking for is not typically an area fat is grafted mainly because it would never look like the photo you have.  Adjusting fat placement for tall patients is a necessity but putting fat that high on the waste will cause a collapse of the love handles.  Not recommended in real life.
Daniel Barrett, MD, MHA, MSCertified, American Board of Plastic Surgery Member, Am. Society of Plastic Surgery