A "2di4" woman is a person that possesses (in the upper echelon) external beauty (ie. considered good looking and knows it). Generally needy and high maintenance with attention seeking thrown into the mix. Men desire her, women often wish they look like her. Despite the external package being well put together, this person is generally a plethora of insecurities. Mental stability or lack thereof can come into play as well.
The girl at the party was simply 2di4. She drew attention by her appearance, but at the same time was insecure about it.