Maybe as 1 possible solution. Place both pic boxes inside a panel and set their correct height and size but have pic1 ahead of Pic2. Then with a timer update their location property so that it appears they are scrolling. When picbox2's location (x) position gets to where you want it to be - disable the timer.

You will have to play around with the settings of the timer and the location but it should work quite well.
vb Code:
  1. Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) _
  2.     Handles Timer1.Tick
  3.  
  4.         If Not Me.PictureBox2.Location.X >= 300 Then  'set to the correct value
  5.             Me.PictureBox1.Location = New Point(Me.PictureBox1.Location.X + 20, Me.PictureBox1.Location.Y)
  6.             Me.PictureBox2.Location = New Point(Me.PictureBox2.Location.X + 20, Me.PictureBox2.Location.Y)
  7.  
  8.         Else
  9.             Timer1.Enabled = False
  10.         End If
  11.  
  12.     End Sub