A new person is interested in getting to know you better, although they don't quite know how to communicate that effectively. In fact, their cool attitude has been sending you the wrong message, entirely! They've been aloof when what they really want is to connect with you. So if you're interested, it's up to you to make the first move. Don't worry about rejection -- just give them a chance to have a conversation with you. If they take it, good. If they don't, then at least they had their chance!