image - Java wrong view JPanel

I have a desktop application in swing. I have a JPanel in which the image as the background and in it two buttons and a JScrollPane as shown in the picture Frame with JPanel. I have a function (showLabel()) which, when JScrollPane the end, add JLabel with transparent images and disappear a few seconds. The problem is that when you add JLabel. JLabel bad shows as seen in Fig Bad shows. Can you help me with my problem?

 public class MainWindow {

 private JFrame frame;
 private PanelPopis panelPopis = new PanelPopis(this);
 private MyPaint myPaint;


 public MainWindow {

    setWindow():
    BufferedImage image1 = ImageIO.read(getClass().getClassLoader().getResource("poz.png"));

    this.myPaint = new MyPaint(image1);
    this.frame.add(myPaint);

    this.myPaint.add(panelPopis.setPanel());


}


 private void setWindow() {
    this.frame = new JFrame("DD");
    this.frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    this.frame.setSize(400, 680);
    this.frame.setResizable(false);
    this.frame.setLocationRelativeTo(null);
 }


 private void showLabel(){

   JLabel label = new JLabel();

   label.setIcon(new ImageIcon(new ImageIcon(getClass().getClassLoader().getResource("postEn.png")).getImage().getScaledInstance(395, 653, Image.SCALE_DEFAULT)));
   label.setBackground(new Color(0, 0, 0, 10));
   label.setOpaque(true);

   this.frame.invalidate();

   this.frame.add(label);
   this.frame.revalidate();

    int delay2 = 3000; // milliseconds
    ActionListener taskPerformer2 = new ActionListener() {
        public void actionPerformed(ActionEvent evt) {
            frame.remove(label);
            frame.revalidate();
            frame.repaint();
        }


    };
    Timer myTimer2 = new Timer(delay2, taskPerformer2);
    myTimer2.setRepeats(false);
    myTimer2.start();

}

}

public class MyPaint extends JPanel {

private static final long serialVersionUID = 1L;
BufferedImage image;

public MyPaint(BufferedImage image) {
    setOpaque(false);
}



public void paintComponent(Graphics g) {
    super.paintComponent(g);
        g.drawImage(image, 0, 0, 395, 653, this);

}

}

public class PanelPopis extends JPanel {

private static final long serialVersionUID = 7676683627217636485L;

private JButton setLanguage;
private JButton cont;
private JScrollPane scrolPanel;
private JTextArea popis;
private MainWindow mainWindow;


public PanelPopis(MainWindow mainWindow) {
    this.mainWindow = mainWindow;

}

public JPanel setPanel() {

    JPanel panel = new JPanel();
    panel.setLayout(new BorderLayout());
    panel.setOpaque(false);


    JPanel panel2 = new JPanel();
    Border border = panel2.getBorder();
    Border margin = new EmptyBorder(0, 0, 4, 0);
    panel2.setBorder(new CompoundBorder(border, margin));

    panel2.setOpaque(false);
    panel2.add(this.scrolPanel = new JScrollPane(popis));

    panel.add(this.setLanguage = new JButton("language settings"),   BorderLayout.NORTH);

    panel.add(this.cont = new JButton("CONTINUE"), BorderLayout.SOUTH);
    panel.add(panel2, BorderLayout.CENTER);

    return panel;

}

}