For example, compare the undomesticated minx [1] to the most domesticated one [2]. I have lots of other videos of the in between steps as well where the behavior changes from more and more energy to more and more passive. The same was basically true of the foxes. I apologize for the crappy video and inevitable dropbox bandwidth limit in advance.
[1] https://www.dropbox.com/sc/6o6j9s7ss8ux6ly/AAAvpqD0ybVfZdDqz...
[2] https://www.dropbox.com/sc/ey1nd1irvmw78be/AAADXhtFnGCtkVCh8...
I think these foxes are a lot like that - they love to hide in "dens" provided to them (plastic tubes), but I doubt they have the ability to build shelters or find food in the wild. Hence the less purposeful behavior - what are they going to do in their spare time, solve calculus problems? They play and wait for belly rubs and food. But I don't see the difference with pet dogs which are not bred and raised for specific work.
We don't know why she does this and during the winter she's mostly content to lurk in the house. But during summer she goes out and stays away. She doesn't come to eat or sleep, she's just gone. We've seen her kill hares too, which are almost 1/3 of her body weight perhaps.
So cats (or maybe just this cat) don't lose their 'wild side' no matter how domesticated they become.