Here is a code that displays an image on internal frame.

import java.awt.*;
import java.io.*;
import javax.imageio.*;
import javax.swing.*;

public class ImageInJInternalFrame extends JDesktopPane {

    public static void main(final String[] args) throws IOException {
        final ImageInJInternalFrame desktop = new ImageInJInternalFrame();
        desktop.addPicture(ImageIO.read(new File("c:/bird.png")));
        final JFrame frame = new JFrame("Show Image");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.add(BorderLayout.CENTER, desktop);
        frame.setSize(400, 200);
        frame.setVisible(true);
    }

    public void addPicture(final Image image) {
        add(createFrame(image));
    }

    private static int frames;

    private JInternalFrame createFrame(final Image image) {
        final JInternalFrame frame = new JInternalFrame("Picture ");
        frame.add(BorderLayout.CENTER, new JLabel(new ImageIcon(image)));
        frame.pack();
        frame.setVisible(true);
        frame.setLocation(40 * frames, 40 * frames);
        return frame;
    }
}