In my case, I'm so much into the idea of depriving girls of their human dignity, so I like it better when such a cage contains girl whose hands tied behind her back, so she has to eat food from a bowl or ground like a dog.
I'd like to see a bucket or just some hay scattered on the floor, suggesting she has to perform her bodily functions in front of her captor's eyes. And she better be caged in such a condition without having a chance to wash her body - her hair all oily and matted, her body glistening with sweat and filth, spreading her strong feminine scent among the stench.
...I know I'm just gross