In Assassin's Creed Black Flag Resynced, Portraits are a new type of collectible featuring important characters from Edward Kenway's story. There are 11 Character Portraits in total, and they are separate from the regular Paintings and Art Pieces found throughout the game.
Most Portraits are obtained after progressing through the story and defeating the character shown in the portrait. A few are instead rewards from side quests, including the portraits of Blackbeard, Stede Bonnet, and Robert Maynard. Unlike many other collectibles, Portraits aren't automatically revealed when you synchronize a Viewpoint - you generally need to get close to their locations or know where to look.
Once you collect them, you can return to Great Inagua Manor and hang the Portraits in the empty frames around the mansion. Displaying all 11 unlocks "The Memory of My Enemy" achievement/trophy and rewards you with Haytham Kenway's Overcoat, as well as a special treasure map - Portraits Treasure Map - Great Inagua.
Note: Each portrait's description tells you where it needs to be hung.
