I would have to agree with the marketing aspect as well.
There's the old marketing adage that "sex sells".
Well, arguably, so does cute.
I suppose there's also the possibility that they wanted to plant the seed in people's minds that their vacuums were good for cleaning up pet hair, or when little Fido knocks over a potted plant.
And, like Husky said, it sort of hits people in the feels with the image of a happy, wholesome, family home.