Why do I have skin folding in vertically after full tummy tuck with ab tightening? (photos)

A ten pound weight loss typically would not cause this type of result unless there was significant loose skin present prior to your tummy tuck. Did you have a large amount of weight loss prior to your tummy tuck? It may be that you needed to have it addressed via a fleur de lis incision.

Thank you for your question and posting appropriate pictures. Some patients anatomy especially ones with horizontal skin laxity can have this issue after surgery. Depending on physical examination this may be remedied. Few options exist including laser liposuction, reverse abdominoplasty, Fleur de lis abdominoplasty or revision lateral tension abdominoplasty. 

10 lb weight loss is not substantial - this vertical line could be result of less than optimal abdominal flap mobilization and 'redraping' over the plicated abdominal muscles. 

The vector of force with the conventional abdominoplasty is up-and-down. Horizontal laxity can be manifest as vertical contour irregularities such as in the picture provided.

Only IN PERSON evaluations would allow a determination of the reason for these results...Best to seek a few...