For me, this tends to be a post-prandial or late night beverage, when one feels the need for a little pick-me-up.
It’s best if you can plan ahead and make the espresso beforehand, so it has a chance to cool before putting the drink together. If not, you’ll find that the ice will melt too much, resulting in a watery disappointment and not the rich velvety delight that it should be.