Why this photo of a toddler at an airport is going viral.

A photo of a baby and a stranger at an airport has gone viral after her father shared the photo with a heartwarming message about friendship.

Dad Kevin Armentrout explained in a Facebook post that while waiting for a plane at a US airport, his 16-month-old daughter Carter Jean was “being her usual inquisitive self” and going up to people to say “hi”.

But when she reached a man named Joseph from Oklahoma, he decided to take the time to occupy the little girl, pulling out his tablet to play with her.

“He reached out and asked if she wanted to sit with him. He pulled out his tablet and showed her how to draw with it, they watched cartoons together, and she offered him snacks,” the US Marine Corps veteran wrote.

“This wasn’t a short little exchange, this was 45 minutes.”

The author and motivational speaker said that this exchange made him think about the best of humanity and the world he wanted for his daughter.

“Watching them in that moment, I couldn’t help but think, different genders, different races, different generations, and the best of friends. This is the world I want for her.”

“In a country that is continuously fed that it’s so deeply divided by beliefs, I want her life to be filled with moments like this… not liberal or conservative republican or democrat, socialist or capitalist, just HUMAN.”

Kevin concluded by thanking the man “for showing my daughter what kindness and compassion looks like”.

“Continue to shine your light in the world.”

Within the five days since Kevin posted the photo and story on Facebook it has been shared more than 159,000 times, liked more than 400,000 times and received more than 13,000 comments.

One comment came from a woman who said she was the tablet-owner’s sister-in-law saying she was “not surprised”.

“Joseph Pat Wright (my brother in law) is a Christian man who treats everyone as a friend. He’s a true blessing and your little girl is an angel herself! She’ll have a friend forever in him,” the woman wrote.

Other people shared their own stories of helping or receiving help from strangers during the stressful situation that is travelling with babies and toddlers.

“As a single mom, I was flying from NYC to Texas during rather bad weather with my very young son,” one woman’s tale began. “Our plane was delayed and I ran low on diapers and formula. My son was understandably cranky and hungry and wet.

“Without words, an older woman wearing a sari, not speaking English, helped me to sooth, change, feed my child throughout the flight. She was amazing and I was so thankful for her.”

Others were simply touched by the story and thanked Kevin for sharing it.