In a medium bowl, whisk the vanilla pudding mix, coconut milk, whole milk, and mango juice together until smooth and thickened, about 2 minutes. Refrigerate for at least 15 minutes to set.
In a large mixing bowl, beat the heavy whipping cream, cream of coconut, powdered sugar, and vanilla extract with a hand or stand mixer until stiff peaks form. Refrigerate until ready to use.
Arrange half the pound cake cubes in the bottom of a large trifle dish or glass bowl. Drizzle with half the mango juice.
Spread half the mango custard evenly over the cake.
Scatter half the fresh diced mango over the custard.
Spoon half the coconut whipped cream over the mango. Layer the remaining pound cake, mango juice, mango custard, fresh mango, and coconut whipped cream.
Top with a generous crown of whipped topping, toasted coconut flakes, diced mango, and fresh mint. Refrigerate for at least 1 hour before serving to allow the layers to set and meld together.