Add nectar, yogurt, milk and 3 cups ice to blender. Blend until smooth and frothy, about 2 minutes; divide evenly among 4 glasses.
Quickly rinse out blender and add strawberries, lemon juice and 1 cup ice.. Blend until smooth and frothy, about 1 minute.
Immediately spoon strawberry puree evenly over top of each shake. Serve.