Swing display issuses

public void startApplication()
{
    loadGUI();
}

private void loadGUI()
{
     frame = new JFrame (getGuiHeader());
     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
     frame.setResizable(false);
	
    frame.setIconImage(frameLogo);
    frame.setLayout (new BorderLayout());
		
    frame.pack();
    frame.setVisible(getFrameVisible());
   
    frame.setSize(getGuiXSize(), getGuiYSize());
		
    new HomeScreen();
		
}

public static void loadScreenTemplate()
{
   JButton viewLeageButton = new JButton("View League");
			
   JPanel menuBar = new JPanel();
   menuBar.add(viewLeageButton);
   
   frame.getContentPane().add(menuBar,  BorderLayout.NORTH);
}


   public HomeScreen()
   {
      guiSetup.loadScreenTemplate();
      JPanel mainContent = new JPanel();
      JLabel imageLabel = new JLabel(new ImageIcon("footballPitch.png"));
		
    mainContent.add(imageLabel);
    guiSetup.frame.getContentPane().add(mainContent,  BorderLayout.CENTER);
   }