I said yes. I always called it grinning. Muffin had a very strong personality. Whenever I'd talk to her in my silly voice, she'd pull up her upper lip and grin at me so cute. I always wish I'd taken pictures of it, but I took it for granted. I can still remember the first time she did it and I was so amazed! I was saying to everybody, "Look! She's grinning at me!"
See this laughing smiley? That's the way she looked!