Okay so I recently fought cackletta several days ago and it got me thinking cackletta's soul is inside bowser's body and I remember when I fought fawful and the dark star physically you were in his body however in superstar saga it's a but different and unique.

Notice how it looks nothing like bowser's body in BIS no tissues or any parts of his internal body 

There's the floor that kinda resembles a shell but the whole landscape looks like some kind of dimension what if this place is cackletta's psyche what if this landscape is part of her mind by inhaling the bros we entered her mind and that's where her soul could reside or she could have some pocket dimension inside her.

It makes sense because cackletta is possessing bowser and this place could very well be connected to her mind or just be a pocket dimension she has and pulled the bros in when she swallowed them when you fight dark fawful it looks nothing like that at all.

It's just me speculating I can't prove what this place is but my brain is saying it's a dimension the vibes it's giving off looks like it could be some dimension cackletta has access to it makes sense cavkeltta is a beanish witch after all it wouldn't be far off for her to create a personal dimension inside herself or pull the brothers inside her mind and this is the landscape of her mind and what it looks like 

What could this place be??