Welcome to Halo Answers. What would you like to know?

First off, Cortana isn't completely nude, she just has a general figure of a nude woman, and to answer your original question, she simply chose it. All AIs choose a form in which to represent themselves when they are first activated, and Cortana chose the figure of Doctor Halsey when she was younger, becuase Cortana's neural net is based of off of Doctor Halsey's, and has all her memories, Cortana natrually chose an image of Halsey's past

I beg to differ if you look closely her breasts are anatomically correct.

Ad blocker interference detected!

Wikia is a free-to-use site that makes money from advertising. We have a modified experience for viewers using ad blockers

Wikia is not accessible if you’ve made further modifications. Remove the custom ad blocker rule(s) and the page will load as expected.