I saw this on TV last night for the first time then found it on YouTube.
It's so subtle I actually wasn't sure whether what was happening was happening (plus there was some other noise going on in the room.)
Have a look, you'll see what I mean.
It's a really very funny idea - and really cute. I think it could have been even cuter if the dog's teeth weren't so scary. But how would I know what a cute, small dog actually looks like when it sings? Check it.