Bake the red velvet cake mix according to package directions and allow to cool.
Using a serrated knife cut the red velvet cake into 1-inch square pieces and line the bottom of the trifle bowl with half of the cake squares.
Using a spatula, spread about a 2-inch layer of whipped topping on top of the cake squares.
Layer about 1 1/2 pints of the blueberries on top of whipped topping.
Layer the remaining cake pieces on top of the blueberries forming a second layer of cake.
Using a spatula, spread remaining whipped topping over the cakes pieces.
Decorate the perimeter with the strawberries; placing the strawberries cut side down. Sprinkle the remaining blueberries on top of the trifle inside the strawberry perimeter.