Try to understand the behaviour of controlpaint.drawreversibleframe() method

See more:

C#

I created a simple windows Form project. the Form is named Form1 with a Button named button1. I put simple test to see how ControlPaint.DrawReversibleFrame() behaves:

if I removed the first statement, consequent frame will not be erased. please help me understand how this reversible Frame works:

ControlPaint.DrawReversibleFrame(rectangle1, SystemColors.Highlight, FrameStyle.Thick);

here is the code:

//
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace DrawReversibleDemo01
{
    public partial class Form1 : Form
    {
        private Rectangle rectangle1 = new Rectangle(70, 70, 100, 150);

        public Form1()
        {
            InitializeComponent();
         
        }

        private void button1_Click(object sender, EventArgs e)
        {
            Rectangle screenRectangle = Screen.PrimaryScreen.Bounds;

            if (screenRectangle.Contains(rectangle1))
            {
                ControlPaint.DrawReversibleFrame(rectangle1, SystemColors.Highlight, FrameStyle.Thick); //<=== if I removed this statement, no frame is erased
                rectangle1.Offset(20, 20);
                ControlPaint.DrawReversibleFrame(rectangle1, SystemColors.Highlight, FrameStyle.Thick);
            }
        }
    }
}

What I have tried:

tried many demos and still did not get firm grip on this method. I feel I missed a critical point somewhere.