I know someone who has Belgian Sheps and she had mum and a daughter and a son from separate litters - the mum used to sit the 2 younger dogs down and wash their faces and ears...... They had expressions a bit ike your dog!!
Sweet, my cat does this to Winston, she holds onto his ear to keep him still. My cats also do this to each other but it sometimes ends up in a cat fight when one gets annoyed!
It's funny how they interact with each other!