I can tell you the story about my yellow pot

Our first Hamster, Charlie, was in a cage very similar to the hamster heaven - same except for smaller bar spacing basically, so I bought the hamster heaven shelf because it fitted. The shelf comes with a hole in for the inset yellow pot (if it is the same yellow pot in your photo!). Also on the shelf was a little plastic pod house that fitted into a hollow. Charlie decided to sleep in that pod house (which was too small for him!) and because the yellow pot/food bowl was in the corner of the shelf he decided it was a toilet and kept peeing in it. So he'd pee all over his food and pee would run out through the bars and sometimes down the shelf as well - which had a slope. I had some tips at the time to put his potty tray over the top of the yellow pot - if that was his pee corner, and give him a separate food bowl. Which I did. That sort of worked at first but he kept moving the potty tray out of the way and flipping the yellow pot out of the hole

. Each day I'd put it back again and find the same thing had happened the next day. He would go underneath the shelf and push it out from underneath!
It wasn't working either as he would move the potty out of the way and still pee in that corner and the pee would run down the shelf (which had a slope for some weird reason) and one day I saw him actually aquaplaning down the shelf, sat in the potty, as the shelf got so wet! It was all a great game!
The pod house kept falling off as well after he stuffed it with bedding and that used to upset him. So in the end I just removed the whole shelf and put a large flat top wood house in instead, which doubled up as a shelf. He immediately moved in and moved his pee corner into a corner of the house so I put his litter tray inside the house. And that worked well. It was a big learning curve with a first hamster
I think Coco's hamster also used to flip the yellow pot out of the hole