Portraits have been important to societies as forms of showing importance, wealth, family, and an overall depiction of who the subjects are as a person. Portraits could be for personal enjoyment to be displayed in their own house, but they were also used to spread their importance seen when placed on forms of money.
Depictions could change based on the artist as their view of the person would influence how they showed them. Showing them as educated, with a skill, as intimidating, or funny could all come out in portraits. Whether depicting themselves or having a portrait made by someone else, interpretation of self came into play.
This can be noticed today still with the importance of the camera. Selfies and photos of others are the continuation of portraits throughout time. Depictions of someone in portraits still changes by who the artist is.