What is when a girl says hey you?

As an AI language model, I don't have access to the specific context of when a girl says "hey you", but generally speaking, the phrase "hey you" is a casual, informal greeting phrase used to get someone's attention or initiate conversation. It could be used in a variety of situations, such as to greet a friend or someone you know, or as a way of introducing yourself to someone new. The tone and intention behind the phrase can vary widely, depending on the relationship, setting, and individual personalities involved. It's important to keep in mind that communication is complex and nuanced, and that there's no one-size-fits-all answer to how to interpret a greeting or any other form of communication.