How to make a cocktail with cheesecloth and a whisk

Courtesy of Cooking Light, whose readers, apparently, do not own shakers or kitchen implements that measure liquid ounces:

[no name given]

1/2 cup El Tesoro tequila blanco
1/3 cup Del Maguey San Luis Del Rio mezcal
6 tablespoons lime juice
6 tablespoons simple syrup
2 teaspoons pomegranate molasses

Combine all ingredients; stir with a whisk. Strain through a cheesecloth-lined colander into a bowl.

Yield: 4 servings (serving size: about 1/3 cup). Calories: 158. Fat: 0g. Protein: 0.1g. Carb: 15.8g. Fiber: 0.1g. Chol: 0mg. Iron: 0.4mg. Sodium: 1mg. Calc: 13mg.

I wonder who this person is who has mezcal and pomegranate molasses on hand, but no shaker? And what exactly are we straining so carefully out of the drink? And where is the ice? So many unanswered questions. But at least we know how much calcium we'll be ingesting.