I guess that you want to draw a thumbnail in the contrainer.
private void panel1_Paint(object sender, PaintEventArgs e)
{
Graphics gc = e.Graphics;
Pen pen = new Pen(Color.Red, 5);
Image image = global::TestGraphic.Properties.Resources.niang;
gc.DrawImage(image, new Rectangle(400, 20, 300, 300));
// chang the 300, 300 to the new image size
}