Place the watermelon cubes and mint leaves into the blender.
Blend until the mixture is smooth and slightly frothy, about 30 seconds, listening for the gentle hum of the blender.
If desired, squeeze a little lime juice into the blender to add a bright, tangy flavor, then quickly pulse to combine.
Pour the smoothie into glasses, observing its vibrant pink color and refreshing aroma.
Garnish with an extra mint sprig or a small watermelon wedge if you like, then serve immediately for the best chilled freshness.
