There are many reasons why a girl might send a purple heart emoji ? to a guy. Here are a few possibilities:
As a sign of affection: The purple heart emoji can be used to convey love or romantic interest, so a girl might send it to a guy she has feelings for to let him know how she feels.
As a way of expressing friendship: The purple heart emoji can also be used to show that someone cares about another person in a non-romantic way. If a girl sends a guy a purple heart emoji, it could be a way of saying "I appreciate you" or "You're important to me."
As part of a friendly conversation: Sometimes people use emojis simply to add color and emotion to their text messages or online chats. If a girl sends a guy a purple heart emoji as part of a friendly conversation, it might not have any particular meaning beyond adding a playful or lighthearted tone to the conversation.
Of course, the meaning behind a purple heart emoji can vary depending on the context and the relationship between the girl and the guy. It's always a good idea to consider the broader context of the conversation before trying to interpret the meaning behind any particular emoji.