My java application creates a frame with a red-dot icon.

If I start the application from the command line, the icon is correctly displayed in the Plama Tasks bar:

But if I start the application from inside IntelliJ, the frame gets an entry in the Plasma tasks bar as well, but its icon is the same as IntelliJ´s one:

Why? My code is simply:

public static void main(String[] args) {
    Image image = new ImageIcon("/home/user/red_circle.png").getImage();
    JFrame jFrame = new JFrame();
    jFrame.setIconImage(image);
    jFrame.setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
    jFrame.setSize(300, 300);
    jFrame.setTitle("Test");
    jFrame.setVisible(true);
}