Combine papaya, lemon juice and sugar in a blender jar. Blend well, adding the pineapple juice, gradually.
Add a few ice cubes and blend again. Add coconut milk and blend to mix. Transfer into a jug and refrigerate for 10 minutes.
Cut a small piece from a pineapple slice and arrange on the edge of an individual glass alongwith a thin lemon slice. Pour drink in it, decorate the way you like and serve chilled.