Mash half of the mango in a bowl with a fork or puree in a food processor to desired consistency.
Whisk coconut milk beverage and maple syrup into the mashed mango; stir in chia seeds and 1 tablespoon coconut flakes. Cover and refrigerate until thickened, at least 1 hour.
Divide pudding between 2 bowls and top with diced mango and remaining coconut flakes.