Is the Fat in my Chest Building Up Again After Gynecomastia Surgery?

There is no substitute for a physical examination but based on these photographs you may have been partially treated. The most common treatment is a combination liposuction and removal of the remaining breast gland.  In your case the scar along the upper circumference of the areolas and the sunken appearance suggests the gland was surgically removed but the presence of a peripheral fullness suggests the fatty portion of the breasts was not entirely liposuctioned off. By two months the swelling is nt ugly resolved but is beginning to clear up. You will need to discuss it with your surgeon and together decide what should be done when the swelling fully resolves. 

In my experience the most common cause of recurrence in cases such as yours is incomplete resection of tissue t the original operation.  Based on your photographs that is what I suspect. In cases of incomplete resection the treatment is to resect the residual tissue.