I like using ingredients having the similar flavors when making a cocktail. Sometimes, it is an overkill, but sometimes the outburst of the flavor is so great that I really enjoy it. This cocktail is a good example of the latter; having the pink grapefruit as the main flavor with gin, aperitivo and fresh juice. And supporting it with citrus ingredients definitely adds on it. The final touch of rosemary garnish is almost a must as far as grapefruit is concerned.