Hi DaveinWinston1,
Thank you for the screenshot information.
In Photo Gallery, the shadows on the lower side and right side of the image are by design and cannot be removed.
Maybe you're a very nostalgic user, and even though Photo Gallery is still available on Windows 10 after you've deployed it on your computer in some way, But please allow me to recommend the "Photos" App that is currently widely used in Windows10 and Windows 11, which can often be used as the first choice for viewing pictures:
When using it, you will notice that the image does not show shadows on the lower and right side when displayed.
Best regards,
Mitchell - | Microsoft community support expert from MSFT