' Make picVisible fill the form.
Private Sub Form_Resize()
    picVisible.Move 0, 0, ScaleWidth, ScaleHeight
End Sub

' Copy the image into picVisible.
Private Sub picVisible_Resize()
    picVisible.PaintPicture picHidden.Picture, _
        0, 0, picVisible.ScaleWidth, _
        picVisible.ScaleHeight, _
        0, 0, picHidden.ScaleWidth, _
        picHidden.ScaleHeight, vbSrcCopy
End Sub