put prefab in top left of the camera

I am trying to put a prefab in the top left corner of the camera, i have the next code:

 Encounter encounter;
 Party party;
 public Portrait portraitPrefab;
 Portrait[] Enemies;
 // Use this for initialization
 void Start () {
     encounter = EncounterStatic.encounter;
     Enemies = new Portrait[encounter.getEnemies().Length];
     Renderer portraitRenderer = portraitPrefab.GetComponent<Renderer> ();
     float portraitWidth = portraitRenderer.bounds.size.x;
     float portraitHeight = portraitRenderer.bounds.size.y;
     Bounds bound = CameraExtensions.OrthographicBounds (Camera.main);
     float posX = bound.center.x - bound.extents.x + portraitWidth / 2;
     float posY = bound.center.y + bound.extents.y - portraitHeight / 2;
     Vector3 upperLeft = new Vector3 (posX,posY,0);
     for (int i=0; i<encounter.getEnemies().Length; i++) {
         Portrait newEnemy = (Portrait)Instantiate(portraitPrefab,upperLeft,transform.rotation);
     }
 }

Everything is working ok but for some reason i get the portrait a lil bit too on the left, whats wrong with the code and why it works only on the Y axis?

graphical description of the problem: