This works I think:
1. Add a page header
2. Add a textbox to the page header, positioned top left and filling the width of the header
3. Populate the textbox expression with whatever you want
e.g. : =iif(Globals!PageNumber=1,"","This is a normal page header on page " & Globals!PageNumber)
4. Set the visibility of the textbox based on the expression : =Globals!PageNumber=1
5. Add an image to the page header and position it top left so it overlaps the textbox.
6. Set the picture to display and set the size to your requirements
7. Set the visibility of the image using the expression : =Globals!PageNumber>1
8. Drag the bottom edge of the header right up to the bottom of the image.
That should do it.
MM
select geometry::STGeomFromWKB(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