Da Mao, the four-year-old male, strutted outside and ate bamboo, basking in the attention from dozens of guests at an invitation-only event.
His prospective mate, five-year-old Er Shun, stayed inside in a separate enclosure, almost hidden in a pile of logs as she munched on her own pile of plants.
Pandas are solitary by nature and must be kept apart except when mating, zoo staff said. But choosing which one would take centre stage was also a matter of character, they said.
As the zoo's latest stars settle into their sprawling new home, their personalities have begun to emerge — and they couldn't be more different, said William Rapley, the zoo's executive director of conservation, education and wildlife.
"They're quite different in their behaviour, and animals vary a lot. The male, Da Mao, is very outgoing, he's kind of a rock star," he said.
Er Shun, meanwhile, is shy and "tends to want to not be with maybe as many people or whatever so far, but she's going to adjust to that," he said.
The pandas arrived in Canada in March on a special flight from China, and will spend five years at the Toronto Zoo. They will then be moved to the Calgary Zoo, which has announced a major redesign to house the new visitors.
The Toronto and Calgary zoos played host to pandas in 1985 and 1988, respectively, while another couple took up a brief residence at the Winnipeg Zoo in 1989.
The pandas' arrival was touted by Canadian and Chinese officials alike as a sign that ties between the two countries are getting stronger.
Thursday's preview was for politicians, dignitaries and the media, who lined up four-deep to catch a glimpse of the endangered bears.
Thousands of zoo members have signed up for a sneak peek Friday, a day before the exhibit opens to the public.
Despite the scrutiny, Da Mao ambled nonchalantly Thursday through an outdoor enclosure, a grassy hill with a pond, boulders and a cave, drawing comments from the crowd on his "relaxed" demeanour.
The panda habitat also includes several indoor areas and a combination laboratory and nursery space, in the hopes the pair will eventually reproduce.
But breeding them is a tricky process because female pandas are only receptive to the male for 24 to 72 hours each year, said Maria Franke, the zoo's curator of mammals.
"We've just got to be patient and keep our fingers crossed," she said.
Feeding them is another challenge, Franke said.
Pandas are finicky eaters who turn up their noses at most of the bamboo they're given, she said. Even so, they consume 10 to 15 kilograms of bamboo each day, which can take up to 16 hours.
The pair's meals are being flown in from Memphis, Tenn., twice a week, Franke said.
Some amused guests pointed out the bears are getting rock-star treatment.
In a ceremony to introduce the pandas, Chinese ambassador Zhang Junsai joked the animals were being so well cared for in Canada they may never want to return to their homeland.
Note to readers: This is a corrected story. A previous version said the pandas go on public display Friday.Suggest a correction