Congratulations. It looks like you picked a great plastic surgeon and that he did a very aesthetic TT on you. As to why the two sides are uneven, the answer is at this stage, they are never even.
I find the most common reason for significant difference of the two sides at the waistline in a tummy tuck is that they were uneven before surgery, but the fat and extra skin camouflaged the uneveness. Very possibly, you have some level of scoliosis. To check this, have someone take a black magic marker and draw along the most prominent part of the vertebrae from between your shoulders down to your hip bone. I'll bet the line curves to the side with the bigger dent.
If scoliosis if not the answer, then asymmetric swelling is the second most common cause. In my practice, I would use therapeutic ultrasound (the kind physical therapists use for sore muscles) to decrease the swelling at your waistline.
Give yourself a break and give your surgeon a break. It appears you have an incredible result. Just give time, time, and don't forget, there is a depression built in to the first couple weeks after cosmetic surgery. During this depression, most of my patients feel they have chosen the wrong surgeon and the surgery went bad. By the third week, they think maybe I know what I am doing. By the fourth week, they think I could be a genius. Wait a couple weeks and see where your head is at.