Put this code into your event for when you press the key
Code:
        PictureBox1.Image = My.Resources.CHANGINGIMAGE
        Timer1.Interval = 2000 'displays the next image in 2 sec
        Timer1.Enabled = True
and add a timer then add this code
Code:
    Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick
        PictureBox1.Image = My.Resources.BALLIMAGE
    End Sub