For the yogurt cream with blueberries, mix yogurt with powdered sugar. Soak gelatin in cold water, squeeze out and warm in lemon juice until gelatin is liquid. Add to the yogurt.
Whip the cream and fold into the yogurt mixture. Strain the blueberries (except for a few for decoration) and mix with the powdered sugar.
Fill the yogurt cream and blueberries alternately into glasses. Decorate the yogurt cream with blueberries.