Altering the shape of the philtrum can be done

Definitely photos are always beneficial to help a surgeon decide what would be the best solution for a particular problem and to reach the desires of the patient.  You can reduce the size of the philtrum by excising certain portions of the lip to change the appearance. These excisions can occur inside the mouth and can hide quite well.  Sometimes, making incisions under your nose can also help change the shape of the lips to get what you want.

There are also many different lip advancements that can be done to alter the shape of the lips. Injections can be helpful but would really depend what the desired outcome was.  I'm sure if you brought your picture in that a facil plastic surgeon would be able to figure out what was best!