If a shield graft is used to lengthen the nose slightly, what does it look like?

Shield grafts can help define the tip of the nose as well as lengthen the nose. The way the shield graft looks really depends on a number of factors. If placed on the bottom of the tip it can solely lengthen the tip. if it protrudes slightly above the tip cartilages it can help create shape and definition. If it's placed well above the nasal tip it imparts even more shape. The thickness of the skin has a lot to do with how this will look from the outside. With very thick skin, any graft will be camouflaged. If you have thin skin the graft needs to be cushioned under the skin and the edges beveled vary carefully.

Shield grafts are not for lengthening the nose, but for adding definition and sometimes projection (depending on the shape and size) to the nose tip.  Be sure to discuss your goals and concerns with your board certified plastic surgeon and consider the pros and the cons. Be certain your surgeon is properly certified.  I've attached a link where you can start your search. 

 Shield grafts are pieces of cartilage typically taken from the nose, ear, or rib, and are used to enhance or improve tip refinement.  The shape of the graft is fairly consistent, but the  placement may vary, and thus the appearance of the graft will change accordingly.    To increase nasal length, typically a caudal septal graft is  used along with a tip graft to enhance tip appearance.  Although the "look" of a tip graft is somewhat characteristic, it should appear soft and elegant.