Use shapes in a range

I Draw a comic strip and I always scan my drawings and work with them in Corel by placing them in four frames and adding text, so I wrote a little macro that reduces the selected scans and places them inside the frames.

This is the code:

Sub PlaceInFrames()
    
    Dim sr As ShapeRange
    Dim s1 As Shape, s2 As Shape, s3 As Shape, s4 As Shape
        
    Set sr = ActiveSelectionRange
    
    sr.Stretch 0.598
        
    Set s1 = ActivePage.Shapes("Rectangle1")
    Set s2 = ActivePage.Shapes("Rectangle2")
    Set s3 = ActivePage.Shapes("Rectangle3")
    Set s4 = ActivePage.Shapes("Rectangle4")
       
    sr(1).AlignToShape cdrAlignBottom + cdrAlignHCenter, s1
    sr(1).AddToPowerClip s1
    sr(2).AlignToShape cdrAlignBottom + cdrAlignHCenter, s2
    sr(2).AddToPowerClip s2
    sr(3).AlignToShape cdrAlignBottom + cdrAlignHCenter, s3
    sr(3).AddToPowerClip s3
    sr(4).AlignToShape cdrAlignBottom + cdrAlignHCenter, s4
    sr(4).AddToPowerClip s4
    
        
End Sub

This code didn't work, I had to define four additional shape variables from each one of the selected range and then work with them.

This is the code that works:

Sub PlaceInFrames()
    
    Dim sr As ShapeRange
    Dim s1 As Shape, s2 As Shape, s3 As Shape, s4 As Shape
    Dim sr1 As Shape, sr2 As Shape, sr3 As Shape, sr4 As Shape
    
    Set sr = ActiveSelectionRange
    
    sr.Stretch 0.598
        
    Set sr1 = ActiveSelectionRange(1)
    Set sr2 = ActiveSelectionRange(2)
    Set sr3 = ActiveSelectionRange(3)
    Set sr4 = ActiveSelectionRange(4)
    Set sr = Nothing
    Set s1 = ActivePage.Shapes("Rectangle1")
    Set s2 = ActivePage.Shapes("Rectangle2")
    Set s3 = ActivePage.Shapes("Rectangle3")
    Set s4 = ActivePage.Shapes("Rectangle4")
       
    sr1.AlignToShape cdrAlignBottom + cdrAlignHCenter, s1
    sr1.AddToPowerClip s1
    sr2.AlignToShape cdrAlignBottom + cdrAlignHCenter, s2
    sr2.AddToPowerClip s2
    sr3.AlignToShape cdrAlignBottom + cdrAlignHCenter, s3
    sr3.AddToPowerClip s3
    sr4.AlignToShape cdrAlignBottom + cdrAlignHCenter, s4
    sr4.AddToPowerClip s4
    
End Sub

Why didn't it work the first time when I tried to use the four items in the ShapeRange? Remember I'm totally new to VBA or any form of programming.

Thanks

I forgot to explain this: The "activeselectionrange" that I use for my variable "sr" is the four scans that I import in my document and then select them all at the same time.