Girl's Behavior

What does a hug from behind means?

So I have this female friend, we just met a couple of months ago, but we're really comfortable with each other that our classmates tend to assume we're together. She sometimes tease but I think it's just her naughty personality. One time she asked me to drive with her home because she's scared of driving alone and when we parked, I went out but she called me to get in again, then she just started playfully hitting me and snatched a kiss on my cheeks. It was not awkward (I think) Recently she was having a rough time and she told me she needs someone to talk to, so we talked for hours. She asked me to give her a hug the following day, but I just patted her on the back. Later that day she asked me if I could come with her, but I was already in class. After that she's a bit cold. She didn't attend our class twice. So I made a new female friend, and invited her to come along with us, but she makes excuses (plus she talks bad about the other girl, calling her social climber et al). She's somehow avoiding me. Today, we have a common class, usually we'd go there together but she came in late. I said hi to her but she's not as jolly as before. She went back to me and asked for my notes, as she was getting it in my bag her chest wrapped my leg. She's still not as talkative as before. So when we were called to do boardworks, I initiated to talk and touch her to loosen her up. She put her arms around me and said "I miss you, bro" So I smiled to her then when I turned around she hugged me from behind. It was actually a warm and lingering hug.
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+1 y
She also sometimes bring me my favourite food. But she talks about other guys (esp her crushes and flings) plus she says yuck when our friends tease us. Am I this little/big bro figure or gay friend figure to her?
What does a hug from behind means?
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