No ideas. Sorry.
Lisl does this when she wants me to engage her. Usually while I'm sitting on the couch next to her wrapped up in this site on my laptop or watching TV.
It's like a little kid tugging on your pants leg. "Hey Dad, play with me or pet me awhile"
Bear, Anna, Molly, Ossie, and The Countess Lisl von Schlaf
An Unhappy German is a Sour Kraut!