In the photo, the wild cat's huge paws are clamped onto the side of the white safari Jeep in which Chappell was a passenger. Almost as tall as the Jeep on her hind legs, she appears to be forcing her muzzle into the back window.
Chappell, 29, was taking photos of a pride last week at Lion Park in South Africa's Gauteng province when one of the animals leaped up against the vehicle and fatally attacked her, according to accounts of the attack. She was in South Africa on a volunteer mission to protect wildlife.
Her family is heartbroken.
"Katie was a brilliant, kind, adventurous and high-spirited woman," a family member said in a Facebook post. "Her energy and passion could not be contained by mere continents or oceans."
A memorial service was held Saturday in her hometown of Rye, New York.
"She was very much loved and shared her love for life with those she met," her family said.
Chappell was a visual-effects engineer who had worked on such movies as "Godzilla," "Divergent" and "Captain America: The Winter Soldier," according to her Internet Movie Database profile
. Most recently she was employed by visual-effects firm Scanline VFX, where her team won an Emmy
for its work on an episode of the fourth season of "Game of Thrones."
"Kate was a valued member of our team and we are devastated by the loss. Our hearts and prayers go out to her family," said Scott Miller, studio manager at Scanline VFX, in a statement sent to CNN.
Witnesses honked horns as lion drew near
Details are still emerging of what happened June 1 at the South African preserve. An investigation by authorities is underway.
A South African tour operator, Pierre Potgieter, 66, was driving Chappell around the park. Inside the lion enclosures, they stopped to view a group of the animals.
At that point, Chappell "rolled down the passenger window in order to take photographs," according to Potgieter's company, Kalabash Tours.
But she apparently didn't notice that one of the lions was approaching the vehicle from the side.
Witnesses in other vehicles honked their horns, trying to get the attention of Chappell and Potgieter as the animal got nearer, according to a source close to the investigation, who spoke on the condition of anonymity.
The lion stopped about a meter from the vehicle as Chappell continued taking pictures, a Lion Park statement said. The animal then lunged at the car, biting the woman through the open window.
Tour guide suffered injuries
Potgeiter said he tried to fend the lion off, suffering injuries to his arm as he did so. He may also have suffered a heart attack, Kalabash Tours said.
After the lion backed off, Chappell was left bleeding profusely from her neck, and Potgieter applied constant pressure to try to stop it, the tour company said.
An ambulance arrived within minutes, the park said. But it wasn't in time to save Chappell, who died at the scene.
Opening windows 'absolutely forbidden'
Opening windows is a big no-no at Lion Park.
"That's absolutely forbidden at our park," said Scott Simpson, assistant operations manager at Lion Park. "There are numerous signs, and we hand out slips of paper to all guests warning them to keep their windows closed."
The source close to the investigation said the notice warning guests to keep their windows closed was found on the passenger side seat of the vehicle.
There are conflicting accounts over how many of the vehicle's windows were open and when.
Lion Park has cited witnesses as saying that both the passenger's and driver's windows were open.
But Potgieter "strongly denies that they were driving around the lion enclosures with open windows," the tour company said.
Kalabash Tours said Potgieter is "severely traumatized" following the attack and "is not capable of giving a detailed account of the incident at present."
Lion not expected to be killed
Potgieter wants to express "his deepest condolences" to Chappell's family and friends, the company said.
Lion Park said it was "incredibly sad that a life had to be lost in this manner."
Simpson said the lion would be taken to a second property while the park investigates the attack. The animal will not be euthanized.
"Visitors to South Africa need to remember that predators are dangerous and rules are there for their own safety," the park said. "If all the rules are adhered to (during) your visit to the Lion Park, national parks and other similar facilities will be a safe and treasured experience."