For example: if you pick a human as your character, and choose her/him to be poor (street rat), you can give the character clothes that tell that this character is poor. Same with commoner and a noble.
If you pick your character to be an Asura, all the colleges may have their own “school uniform”.
With Charr it depends on legion.
Sylvari and Norn are a bit more difficult… With Norn it would be Defeater of the Ancient Foes, Protector of the Spirits, or Guardian of the Mists.
Sylvari… White Stag Hunter, Green Knight Challenger, or Shield of the Moon.