Where does she come up with these things

So I really don't have much to type about but Mackenzie has started this new thing at bed time. After she climbs (and I mean climb, she really does climb over the toddler rail) she stands up and gives Brian a hug and then she has started rubbing his head. She pulls his head down so she can see the top and then she rubs his hair. We are not really sure what that is all about, but it is funny.