Eine Methode funktioniert eine ähnliche nicht

var school_Pictures = [["garbage-bag-1256041_1920.jpg", "school_1"],
                       ["MBGLogo-grauorange.png", "MBG"],
                       ["Plastic_beads2.jpg", "school_3"],
                       ["plastikgranulat_digitalstock_fotolia_49126273_xxl_0.jpg", "school_4"]]; //Pictures of the schools

//Class for a themefield
class Box
{
  constructor (Id, Pictures, Name)
  {
    this.Id = Id;//Id of the devision where the picture has to been put
    this.pics = Pictures;//list of the possible pictures
    this.name = Name;//ID of the devision where the name has to been put
    this.img_pos = 0;//list iterator
    this.max_img_pos = Pictures.length - 1;//number of listelements
    this.img_ID = "img_" + Id;//ID of the Picture
  }
  change ()//methode for changing the picture
  {
    var img = this.pics[this.img_pos][0];//the picture to use
    var name = this.pics[this.img_pos][1];
    document.getElementById(this.Id).innerHTML = "<img src='" + img + "' width='250px' height='250px' id='" + this.img_ID + "'>";//including the picture in HTML (overwrite) //evt. wieder auf 250px setzen!
    document.getElementById(this.name).innerHTML = "<p>" + name + "</p>";//including the name

    if (this.img_pos < this.max_img_pos)//check for getting the following List-Indexnumber
    {
      this.img_pos ++;//incrementation of the List-Index-Number (iterator)
    }
    else
    {
      this.img_pos = 0;//setting the List-Index-Number to 0 (iterator)
    }

  }
  bigger ()
  {
    var element = document.getElementById(this.img_ID);
    element.animate
    ([
        {
          width: "0px",
          height: "0px",
          margin: "125px"
        },
        {
          width: "250px",
          height: "250px",
          margin: "0px"
        }
      ],
      {
        duration: 1500,
        iterations: 1,
        fill: "forwards"
      }
    );
  }
  lower ()
  {
    var element = document.getElementById(this.img_ID);
    element.animate
    ([
        {
          width: "250px",
          height: "250px",
          margin: "0px"
        },
        {
          width: "0px",
          height: "0px",
          margin: "250px"
        }
      ],
      {
        duration: 1500,
        iterations: 1,
        fill: "forwards"
      }
    );
  }
}

function renew_all ()
{
  schools.change();
  schools.bigger();
  window.setTimeout(schools.lower, 2500);
  window.setTimeout(renew_all, 4000);
  //renew_all();
}

var schools = new Box ("school_pictures", school_Pictures, "name_of_school");//creating an object for the schools-Box

renew_all();