Is this a real clue or a red herring?

I don't remember what room I found this in, but I took a screen shot just in case. We're now at the end of the main game -- have solved the Atelier, opened both Moon doors, found the Blue Will, etc. Never did find a mean for this image, though, not in the main house or underground.

Does this mean something? Did we miss a puzzle somewhere?

https://preview.redd.it/d3hi0wf4myog1.png?width=3024&format=png&auto=webp&s=9a50f9ca05a7247ba1e57321d3fd2f49a36781b1