http://www.scientificamerican.com/article.cfm?id=identical-twins-genes-are-not-identical

According to this article some identical twins vary in their copy no variants. How is this possible  ? If mitosis of an egg can lead to this difference  , why can't mitosis of any cell in our body  ?

If we assume that identical twins are exactly identical, then if we make a clone of a twin, will all three be exactly identical  ?

http://www.scientificamerican.com/article.cfm?id=identical-twins-genes-are-not-identical

According to this article some identical twins show differences with respect to their copy number variants. How is this possible? If mitosis of an egg can lead to this difference, why can't mitosis of any cell in our body?

If we assume that identical twins are exactly identical, then if we make a clone of a twin will all three be exactly identical?