Giffard Lichi-Li is a lychee flavored liqueur, presenting in a valentine-friendly pink. They say the fragrance is of "intense fresh lychee and roses."
Giffard is a French company specializing in a wide variety of liqueurs and eua-de-vie among other products. Some of those extra products are flavored cocktail syrups (or "sirop"). They are generally sweetened with pure cane sugar.