Can it take longer for some people to "drop and fluff"? (photos)

Hello,Your implants were much too large for your anatomic capacity. When this is the case, either the surgeon 'lowers your fold' leaving you with a double bubble and pockets that need to be reconstructed, or not, leaving you with high positioned implants. You are latter category, fortunately. At six months, you should have a revision surgery to remove and replace your implants for smaller ones, by an ABPS certified/ASAPS member surgeon who specializes in revision breast surgery. Best of luck!

Generally speaking, breast implants will "drop" into the pocket that was created during surgery and massaging the implants and downward may assist in the dropping of the implants after surgery (for those patients who want to help with the settling of the implants).  As you mentioned, the rate of breast implant "settling" may depend on factors such as size of breast implant pocket dissected, tightness of the overlying skin/muscle layers, size of breast implant utilized, and concerns such as pre-existing breast asymmetry.
Normally, it takes about 3-6 months (for some patients longer) to see the final result. It is very common for one side to settle faster than the other.
Sometimes, one or both breasts implants do not settle as planned and revisionary breast surgery becomes necessary to improve the outcome. On other occasions, if the long-term breast asymmetry is mild (understanding that absolute symmetry is very rarely achieved), patients will need to decide whether proceeding with revisionary breast surgery is worth the potential downsides associated with additional surgery.
Again, best to follow your plastic surgeon for more specifics. Best wishes for an outcome that you will be pleased with long-term.

At 6 weeks, you are about 35 percent settled, shaped, softened, dropped and fluffed. "Drop and fluff" refers to the fact that as the skin stretches and the muscles relax, the implants move down and out slowly – about 1 percent a day. It’ll be about six weeks before they even begin to settle down, but they’ll be close to 80 percent settled and softened at three months. Watching their progress is like watching your hair grow. You don’t see a difference in your hair growth daily, but all of a sudden you need a haircut. 
Be patient after surgery. Give yourself a few months before making a judgment about your surgical results. You won't know the outcome until then. 
Dr. Ted Eisenberg, Board Certified Plastic Surgeon and Author