Mix the crushed ice cubes with finely cut pineapple slices, lemon and pineapple juice and sugar, add well chilled milk, yoghurt, mix briefly, serve with ice in a pre-chilled glass with a straw or spoon, decorate with pineapple pieces if you like.
In this case, serve with a spoon. If a blender is not available, use pineapple pulp.