I have this exact piece! It is still in the original door in my 1912 Victorian.
With yours, someone didn’t want the decorative outside door but kept the beautiful glass pane. Usually it’s the glass that is missing or replaced with a plain pane due to breakage. It’s wonderful that someone saved this.
Super cool well if you ever need a replacement you know we're to find one lol. It's just gonna be hanging on my wall! Also just curious we're your located? I would love to find out the maker. I found this at a Garage sale for $10 in north central minnesota.