The following is based on Van Buren and has not been confirmed by canon sources.
The Prisoner was the running name for the player character in Van Buren, Black Isle's canceled Fallout 3. Unlike the Chosen One, this player's character was not to be a descendant of the Vault Dweller, or any of the Vault 13 residents. Despite that fact, the Prisoner wears a jumpsuit with similar colors to vault jumpsuits with a number 13 on the back. This is because the Prisoner was assigned to cell 13 in Tibbets Facility. This is most likely a reference to Vault 13 from Fallout.
If the prisoner chooses to be male in the tech demo, his dialogue icon is an image of Eric Wu, creator of the popular website Eric Conveys an Emotion. Specifically, the image being used features Eric being smarmy.