It's because he's getting a new face. What you are actually looking at is a pedicle graft, a procedure developed by Dr. Harold Gillies to treat disfigured soldiers during World War I, back when skin grafts and reconstructive plastic surgery had about a zero percent success rate. First, a flap of skin from an unaffected area of the patient's body was sewn into a tube and temporarily grafted to wherever the new body part was needed:
You just have to look like a Seussian horror elephant for a month or so.
The tube maintained a blood supply to the grafted area, which dramatically decreased the chance of rejection and/or infection while simultaneously increasing the number of children that would never come near you ever again.
Despite the "before" pictures having all the grace and subtlety of Eli Roth, the "after" photos of Gillies' procedure are strikingly impressive, especially considering he came up with it almost a hundred freaking years ago. Patients would go from huge gaping hole in their face, to the grotesque sewn-on graft ...
This guy's potential employers are basically limited to Sauron or Gringotts.