Is this swelling or fat left behind? (Photo)

If the area is still numb it is an indication that there still may be swelling present.  If after all sensation returns and there is no tenderness and the skin and soft tissues are soft and supple,  there is still fullness there,  then a small touch up may be in order. 

At only 7 weeks not sure. But after 3 months or 12 weeks it would be excess fat if not one or residual fat.

Hi-Thanks for the question. From the photo you have sent it is really difficult to say. Need to look at both sides to compare. It takes up to 6-9 months for everything to settle down after liposuction. I am sure your surgeon will  only be too happy to see you and reassure you.