What does it mean when a girl says woof/barks at another girl?

I have a friend/co-worker that does this to me occasionally. The latest time she did it, I asked her why and she wouldn't answer.
She was coming in as I was leaving, and we were both heading to the break room at the same time. She caught up with me to do it. Had normal conversations and interactions after that.
She is a lesbian, and we tend to be friendly/flirty and playful with each other.
Updates
+1 y
She tends to treat me different/better than other co-workers, and does things to get my attention.
What does it mean when a girl says woof/barks at another girl?
Post Opinion