Juvederm is a brand of injectable, hyaluronic acid-based dermal fillers used for cosmetic enhancement. 
It can be used to add volume and definition, improve lip symmetry and contour, and reduce the appearance of fine lines around the mouth. 
A lip flip is a non-surgical cosmetic procedure that uses small amounts of a neurotoxin like Botox to relax the muscles around the upper lip. This causes the lip to subtly "flip" or roll upward, creating the illusion of a fuller lip and a more visible pout without adding volume. It can also help reduce a "gummy smile" by preventing the upper lip from retracting too much when smiling.