It looks as though you Have gotten a good result. Dr. RAND in his previous comment is completely accurate and the restoration of abdominal wall contour from the abdominoplasty can unmask this normal physiologic phenomenon.
as far as it can be seen in your pictures you are having good results, what you describe can be caused because you are eating and now you notice that the abdomen grows after the food is in your stomach,it could also be possible that swelling makes your belly more remarkable after eating, remember that swelling can be present for up to six months and in some cases even later. Best wishes!