Girls, What does it mean when a girl is following me, but ignoring me?

[Anonymous]

There's this girl who works at the gym and caught my eye when I first saw her. She seemed kind of cold at first until I approached her and her friend with a question last Thursday. The next day she acted completely different, smiling at me. On Monday she became more distant and today she was completely ignoring me. But she wasn't avoiding me, everywhere I went, she was there in like 10 minutes. I said hi three times and she didn't respond, so I asked her friend if I did something to irritate her and she told me that "she's not like that, maybe she's just overworked".
She responded to me only when I said bye on my way out.
I want to know if she is telling me to get lost, playing hard to get or looking for my attention?
What's the best way to approach a girl who's doing this?
I have to add that I don't talk a lot with people at the gym, because I'm a bit introverted.

[hazal21]

It's quiet hard to explain. But i think she's playing hard to get. because wherever u go she's there within 10 minutes it means she's a little bit interested in you and actually she follows you maybe she wants you to approach her and talk to her.
Ask her friend again if she's even interested to start a conversation with you because you said hi 3 times and she didn't respond. ask her friend that why is she being like this?
And if she does that continuously then ignore her.

[Asker]

I don't think that asking her friend will help, because I think she's helping her play the game. She probably told her I asked about her. I don't know if this good or bad, because she could be checking either if I'm interested or I'm good enough for her.

[hazal21]

Again try to say hi try to approach her. If she ignores you again then you do the same. Ignore her as well. Ignore her for a few weeks. If she is interested in you she will glance at you everytime and if not then just ignore that boring girl.