Keeping things interesting
Yes, ignore the pooch and now he will plant and muster his newly deep voice and bark for attention. This is not nice (although I should stress that it's more of an occasional annoyance than a full-blown crisis).
I thought at first that he was doing this because I'd been away at a seminar in DC, and he was a bit clingy when I got back -- as opposed to say, Andrew, my flesh and blood, who merely said, 'Oh, Mom's back.'
But nope, I'm thinking that Murphy just has an innate sense of how to keep things interesting, and how to not let me ever get too confident or too zen.