Dior describes it as:
A made-to-measure lip balm that beautifies and durably enhances the lips’ natural color. A customized color result : thanks to its Color Reviver technology, Dior Addict Lip Glow reacts directly with the unique chemistry of each woman’s lips before releasing its color ingredient. Lips seem revived from within, amazingly fresh, full and radiant. In addition, its SPF10 formula enriched with wild mango and luffa cylindrica continuously protects and moisturizes. A universal balm for all lips.
I've always heard (although I didn't put much credit in it) that wearing lipstick fades your lips over time. I haven't seen that but, even if it's true, this does the opposite. It leaves your lips worthy of a book heroine description. Who doesn't want that?