I want to agree, OP doesn't sound like a good roommate and definitely not respectful of their house's established rules. But also I'm somewhere along the lines that this involves a cultural difference.

I'm Chinese-American and something that's fundamentally shared in Chinese culture is reluctance to carry emotions, and it can come across as passive-aggressiveness when it comes to issues and differences. Not that we even call it passive-aggression, it's actually seen as politeness and respectfulness in Chinese culture. For example, my childhood best friend's mom used to be really mad at me for taking food from the pantry while we would hang out. I never thought it was a problem because my friend would be the person to say, "Oh yeah, can you go grab some Lays? And some gatorades?" and we became super familiar at her house. Her mom had a lot of inner resentment built over me but kept her cool all those years out of respect for my mom (they were family friends) and me. Do I agree with this behavior? No. But is it very common in Chinese culture? Yes.

Additionally, my mom's parents/family grew up not being very physically affectionate (very common also). She became a very atypical Chinese mom while I was growing up - she's said so herself - she showed me a lot of physical affection since in her own life, she felt she was missing something in her childhood.

Of course, culture is nuanced and much more complicated than I'm explaining, but I would like to let OP know that taking Chen's demeanor as "standoffish"-ness and passive-aggressive as a personal jab is not going to go anywhere productive. It seems like Chen is a normal girl (that carries common Chinese characteristics) and you've really pushed her buttons as a roommate because you haven't respected the rules that the above post has articulated.