For a decade, Cookie and Stitch shared a water bowl and chew toys. The two dogs even ate their kibble out of the same bowl — and according to their human brother, 18-year-old Easton Dufur, Stitch "taught" Cookie to leave half the food for him.
In early June, Stitch died of old age. The family, who lives in Boise, Idaho, has been reducing how much kibble goes into the bowl since just one dog is eating now.
But Dufur noticed Cookie hasn't yet broken her old habit. She's still eating just half the kibble.
"She is slowly adapting," Dufur, a filmmaker and aspiring actor, told TODAY in an email.
It's impossible not to be moved by the photo of Cookie's half-full food bowl. But what should we make of it?
Barbara King, author of "How Animals Grieve" and "Personalities on the Plate: The Lives & Minds of Animals We Eat," and professor emerita at the College of William and Mary, told TODAY there are a number of possible interpretations.
More TODAY Puppy Dog videos
Watch TODAY puppy Charlie show off his latest skills
Mexico City earthquake: Search for survivors continues
Tennessee church shooting leaves 1 dead, 7 wounded
Trump’s war of words with North Korea continues to increase tensions
One isn't so emotionally stirring to contemplate: Stitch may have been the dominant dog in the relationship with Cookie, and perhaps acted "firmly toward her if she tried to eat more."
"What looks on the surface like grief could just be habit, the ingrained product of a hierarchical relationship over many years," said King.
King has no doubt, however, that animals can and do feel grief. Cookie's behavior could be an indication of her experiencing that feeling at the loss of her longtime companion.
"When one dog dies and the surviving one changes his or her routine markedly — by socially withdrawing, or failing to eat or sleep or play in normal ways for more than a day or two — then I'd be much more likely to go with a mourning explanation," she said.
Dufur isn't sure. He said Cookie's tail is always wagging, which can make it hard for him to read her mood.
Plus, Dufur grants, the dogs always did get a lot of kibble. Maybe Cookie just isn't that hungry. And in any case, he said while Cookie continues to leave half her food, he's noticed her coming back to finish it now. Perhaps she's beginning to realize, or adjust.
Still, he and his parents are "definitely trying to help her," he said. "Especially by giving her more attention and more love so she doesn't feel so lonely."