Jozef Israels painting Children of the Sea question

My dad found this very old painting yesterday, it has been determined it is titled Children of the Sea by Jozef Israels, BUT why is it the exact reverse of all of the images I see online? It measures 12" x 23 1/2". There is a lot of paint loss and appears to be extremely old with some new staples in the corner. First photo is a screenshot for the internet. The rest are mine. Thanks!!

 

I forget the name of the technique, but this is a printed copy probably from the Victorian era. They were made as decorative items and not to fool anyone, although at this point it happens.

 

Thanks I'll try to find out what that's called!

 

I know Jozef Israels painted this subject several times, but this is definitely a reverse copy of the most famous one, which he painted in 1872 while living in The Hague. The original is in the Rijksmuseum in Amsterdam.
I have no idea how your dad's copy came to be a reverse of the original, but I'm sure someone will explain it.

Oleograph maybe? I think those are regular copies, not reverse.

 

Charming scene.

Debora

 

Maybe this:

https://www.easy-oil-painting-techniques.org/how-to-use-a-comparator-mirror.html

 

Here's an article on Oleographs- https://fineart-restoration.co.uk/case-studies/oil-painting-or-oleograph-how-to-tell-the-difference/