Good Lord, could Mary get any smugger? Even her fantasies are thick with loathsome self-regard, as she imagines Chester positively vibrating with delight at the sight of the largest, cheapest bag of dog food she could find at the discount supermarket.
On the other hand, at least ACME dog food is probably just bland and lacking in nutrients, as opposed to the actively disgusting BARFOO food that Marmaduke’s owner is feeding him. Of course, Mary claims to actually like Chester, whereas I have to imagine that Marmaduke’s owner’s attitude towards his enormous, destructive pet is a toxic mix of hatred and terror.