"Come" Sometimes

Emme has decided that the command "Come" only applies sometimes. If I am preparing a meal and call "Emme, Come" she dashes to the kitchen. If I am in the closet and call her from the bedroom, she runs to me as fast as she can. So I know that she knows what the command means and is perfectly able to do it. When she wants.

On the other hand, if she is playing "You'll Never Find Me," she hides somewhere in the house and gleefully waits silently as I call "Emme, Come" and search the house to locate her. I thought that was the only time that "Come" didn't count.

Recently she has decided that "Come" doesn't apply to her if I want her to go outside for a hurry up and it isn't her idea. Three or four times in the last few weeks, I have called her to come and her behavior is exactly the same. She turns her head away from me ("If I can't see you, I can't hear you.") and she walks slowly away in the other direction. She doesn't run; she just meanders like she is taking a stroll, so I won't get the idea that she is running away, just that she hasn't heard me. I only have to say "Emme, no" very quietly to call her on it. I don't have to yell. I just have to let her know that I know she has heard me and she can't ignore me.

What is this about? Come means come all the time. Except when it doesn't.