# Why does Methyl Carbocation have p orbital

For a carbocation to form, it needs to lose an electron. In the example below the leaving group is Br and the products are a methyl carbocation and a bromide ion.

What I am unsure about is why the carbocation needs an empty p orbital. For a carbon atom with 6 valence electrons, the molecular orbital diagram looks like the one below. So when an electron is lost in heterolysis the $$\ce{2p}$$ orbital will be empty and I assume that is why the p orbital is empty. However, why do you include the empty p orbital in the shape. Does it serve a purpose?