I hate when girls do this - stuff like that is actually a common occurrence.
I'd go on the limb of saying that there is no hidden meaning. She might like you. She might not. She might be making fun of you. Maybe not. My experience in human observation says that girls tend to get in engaged conversations with people they find annoying or worthy of ridicule, almost like it's sadistic entertainment to ridicule the other person with (interestingly...) some sort of strange logic. They may engage with you more; they may not. They may simply be experimenting with identity - trying to see who they are through the expressions of others.
There was this girl... actually these girls... at my former school who fit this idea well. In ninth grade during an exceptionally long fire drill I was introduced to a friend of someone whom I knew. A week or so later, I was at the water fountain between the last two periods of the day, when I heard my name being shouted by both of these girls, followed by "is that you......?" in exaggerated, pseudo flirty tones... You know the type. I believe I ran, almost literally, away and it made an interesting story. However, it happened again... and again... and again...
We can place both interpretations to it - flirting, maybe, but also ridicule. Perhaps, if you have the reputation of being strange, socially awkward, loner, whatever, it may be fascinating for them to do stuff like that. I know it would be for me if I met someone more socially awkward than I am...
-aaron