What's the deal with the lucky / 4-leaf clover fountain pond rooms?

[Squashua]

I keep finding rooms with 4-leaf clover designs and ponds with fountains in them; it feels like there should be something significant here, but nothing ever happens. Is there a special purpose to these locations?

[Lucky Thirteen]

Rumor has it that there'll be a chest if you are in favor with Lady Sophie, and indeed, I once saw a blue chest in one of these rooms. I can't recall the exact circumstances though.

I don't think anyone knows this for sure, which is a pitty.

[LazyTavi]

A few times I've seen journal pages refer to "healing fountains" which are "locked away." I'm almost certain it's referring to these places, but I can't figure out what the purpose of it is. A piece of my mind is telling me that the Duck of Doom is somehow related, I can't remember why though.

[Dr777Agon]

That's a special room added for a player (Sir Slush) after he discover the arbitrer ground and a treasure should actually appear by doing something
https://steamcommunity.com/gid/103582791455391913/announcements/detail/1335730452511058495
https://steamcommunity.com/app/506870/discussions/0/1471968797463070195/
For the duck of doom you have to enter the lake of cleansing while wearing it to make something special happend :)