Healer icon is an item worn in the cape slot while playing Barbarian Assault. It shows that the player is a healer indicated by the green circle around them with the healer symbol. It cannot be removed or interacted with in any way besides examining it. When a game of Barbarian Assault finishes, the icon is removed.
Having a higher level in the Healer role, which can be done via Commander Connad or choosing to do so immediately after a game, allows players to heal more hitpoints per healing vial dose.