Preparation Purée mango, sugar, lime juice, and a pinch of salt in a blender until very smooth. Add cream and blend until very thick. Blend in additional lime juice and sugar to taste. Transfer to a bowl and fold in most of blueberries, then divide among 6 glasses. Top with remaining blueberries and zest. If desired, chill, loosely covered, 30 minutes.
Preparation Purée mango, sugar, lime juice, and a pinch of salt in a blender until very smooth. Add cream and blend until very thick. Blend in additional lime juice and sugar to taste. Transfer to a bowl and fold in most of blueberries, then divide among 6 glasses. Top with remaining blueberries and zest. If desired, chill, loosely covered, 30 minutes.