"New Pretty Town"

Why do you think Tally chose to wear a mask to the party that was deamed "white tie"? I think Tally chose to wear the mask , so that no one would see she was an uglie and so that she could talk to Peris.

The History of Masks
A form of disguise. It is an object that is frequently worn over or in front of the face to hide the identity of a person and by its own features to establish another being. This essential characteristic of hiding and revealing personalities or moods is common to all masks.
How does this relate to Tally's decision? I think it relates to Tally's decision because it just tells er it can hide her face very well.