That looks like it actually is some sort of clay pot radiator contraption to throw out some extra heat. I don't know anything about French stoves but it wouldn't be surprising if this is a one of a kind piece of his work. Nothing common about him. Saw some of his work in a gallery exhibition several years ago. Wow, just wow.
Argue for your limitations and they are yours forever.
Location: Wellington, New Zealand
posted 11 months ago
Terracotta pots ares still in use for trapping heat! This is how the "kandle heeter" works.
That stove is very cool. Had to look it up quick, most of the results reference Picasso and that photo. I saw a few places selling them (I think, they weren't in English, and I don't speak anything else). Some photos of ones with a shorter "stack" of radiators. I found this similar design at this site, they are also discussing the photo with Picasso. I couldn't get a direct link to post the image of the other stove here, sorry. My browser kept on downloading a text file when I tried to get the link. Looks like it's also French, and also heating a big room, a church. Couldn't really dig up more, but now I want one.