Double Bubble - could it be muscle attached to the scar? (Photos)

Sometimes a double bubble situation can be a very complicated. It is hard to give you any usable advice without a good examination. The photographs you have taken are not from a good angle to assess a double bubble. Double bubbles have a variety of causes which are usually fixable with revision surgery. It seems you should go with your intuition on deciding whether to see a second opinion plastic surgeon. Good luck with things.

From the submitted photo and description it could be that the issue is as your surgeon advised. However without an exam and more information it's difficult to say for sure. It seems your surgeon is willing to work with you to address the concerns and he has had the benefit of evaluating you in person.

This photo is not sufficient for any meaningful comment and suggestion, unfortunately. However, it may be that postoperative scar attachment is creating breast deformity? A series of better photos or in-person evaluation would help. Good luck.