Is this person purposely trying to start drama?

There's this girl who sits in front of me in my class. I was minding my own business, working. During class she moved to sit beside her friend (right behind me) and I was talking to the girl behind me about a question on the assignment, then when I finished talking, the girl randomly made eye contact with me and said "Your a b**** and I hate you forever"

I barely even reacted, I just shrugged my shoulders, because in all honesty I couldn't care less. Now that I'm looking back on the situation though, was she trying to pull something off? What would be the motive for doing something like that?