Mila is the internet's sassiest toddler. But there's a deeply uncomfortable side to this.

Staring into a camera lens, Mila Stauffer sports a look of grave concern on her little, chubby-cheeked face.

“I saw Sawyer at the park with another girl. I was so mad,” she declares.

She’s wearing a sparkly, velvet dress. A ponytail sprouts from the top of her head. Because Mila is not a teenage girl grappling with boy issues. She is a three-year-old, pretending to be.

Even if you don’t know her name, you’ve almost definitely seen her on your social media feeds.

Just one of her videos can reach seven million views – and that’s on Instagram alone. Add YouTube, Facebook, Twitter and you’re looking at tens of millions.

She’s a new breed of social media star: one made up of little kids who act in viral videos. Coached by her teenage sister at home in Arizona, Mila’s modus operandi is to go on what is typically an adult rant, but with her toddler voice. It’s ironic, it’s funny and above all, it’s very, very cute.

She is a master of the furrowed brow, the eye-roll and the talk-to-the-hand gesture. She uses millennial phrases like “so basic”, “shady” and “shook”. She does all this while discussing relationships, parenting, the gym, football season and school stress.

But increasingly, as more and more videos are made, the glowing comments are being replaced by negative ones.

There is a sense of unease. Why are we laughing at a toddler's attempts to imitate adulthood? Why is she being fed lines and making so many videos on her mum's social media? How much money is she making her family?

Because that’s the thing – when you have three million followers on Instagram, like Mila's mother now does, you can rake in big advertising dollars. Except, social media "influencers" are usually fully-grown men and women who are capable of making business decisions. Not little children.

Mila’s mum Katie Stauffer hasn’t disclosed exactly how much she earns from the social media venture, but she did tell The New York Times in September that the work had become so “lucrative”, she was able to quit her finance job.

“This is my job now,” Ms Stauffer said.

Mila might be the most famous, but she is certainly not alone. There are many examples of parents who set up their child in front of a camera and feed them an adorable script full of language they are too young to comprehend. Cute kids are becoming a legitimate revenue stream.

Seven-year-old Ava Ryan gained a big following by seizing on the exact same concept.

Her most popular alter egos are "Hot Mess Charlene" and "Bossy Boss Lady".

Having now accrued 766,000 followers on her mother's Instagram, she's also appearing in more and more sponsored posts.

Then, there's Caidyn Bennett.

The boy is building up a following after going viral in September with a video deploring people who try to touch his dreadlocks.

"You don't touch a black man's hair," the four-year-old says.

His Instagram page, which lists him as an "actor/comedian", has 23,000 followers. Interestingly, he has also been pictured with Mila.

By all accounts, these are happy, healthy kids. So are we right to feel uncomfortable?

According to two Australian psychologists Mamamia spoke to, the answer is yes.

"It's wildly concerning for a child to be exposed to a broader audience at such a young age," says Ysafe psychologist Jordan Foster.

"It gets marked as a cute, sweet, innocent video. But it's not for the child's benefit."

Psychologist Dr Michael Carr-Gregg put it more harshly, pointing out children do not have the maturity to truly grasp what they're doing.

“The whole thing smacks of exploitation and coercion at that age. I certainly wouldn’t put my kids through that,” Dr Carr-Gregg says.

Most parents take videos of children when they say sweet things. That's by no means unusual or unsafe. But Ms Foster says there is a difference between that and the manufactured nature of these viral videos. Because what might have started out as a kid's cute attitude has evolved into a full, rehearsed script.

LISTEN: 2017 was the year kids became social media stars. Post continues after audio.

Ms Foster's biggest concern is how social media warps children's sense of self-worth, and forces them to cope with online trolls.

"Children are wildly susceptible to the validating nature of likes and shares on social media, which have not only an emotional but also a neurological effect. There's an associated reward response," she says.

Ms Foster says in the long-term, use of social media from a young age is linked to a higher likelihood of depression, anxiety, substance abuse and body image issues - similar to many ill-fated Hollywood child stars. This stems back to the fact children lack the cognitive capacity and resilience to handle so much public exposure.

Some parents would argue that their children love making videos.

In the Stauffer family, Mila's mother says the young star's twin sister rarely appears in videos because she doesn't enjoy making them. Meanwhile, she says Mila only makes them when she wants to - not when the advertisers want her to.

And Mila, it seems, really does love acting in videos. Ms Stauffer last month shared a video of Mila begging her parents to make one.

"Can we do a video right now?" she pleads.

After being turned down several times, she throws a tantrum, tears streaming down her face.

But Ms Foster has her reservations.

"A three-year-old doesn't have the capacity to understand what a video like that is and what her video is becoming."

Ms Foster also worries that this "tantrum" is triggered by a learned need for online validation.

"The scary thing is that ideal is being imposed on her not by active choice but by her parents encouraging and celebrating that."

Dr Carr-Gregg adds that young children have a huge desire to please their mum and dad.

He fears these social media ventures are about meeting the needs of the parents - the digital glory, the financial gain - over those of the children.

"Some kids have a particularly outgoing extrovert personality so of course they love being in the limelight. But you couldn’t expect a child to understand the psychological ramifications," he says.

"You'd think parents would have as their first and most important calling to make sure their children are safe and valued and free from harm."

What's more, these children's names will forever be tied to these videos. If a child grows up to decide they don't want the clips up, it's out of their control. They never actually had a say on the matter, because they were too young.

There are, however, ways parents can help protect their pint-sized internet stars.

Ms Foster's biggest advice is to articulate the quality, instead of the quantity, of positive comments. For example, tell them if a grandparent shares a glowing remark, not the number of likes from strangers on the internet.

Another tactic to prevent too strong an attachment to social media is to push children to focus more on fulfilling activities like sport, academic achievement and family outings.

As for the rest of us, Ms Foster hopes people question their impact when sharing and liking viral videos on social media.

"Are those three minutes of online entertainment coming at the cost of childhood innocence?"

Children like Mila, Caidyn and Ava are healthy, they are happy and they are loved. And it's very possible they will turn out just fine. But what's in store for them is unknown, and it's precisely this future uncertainty that has experts pleading for caution.

What do you think of the new trend in children becoming social media stars? Tell us in the comments below.

Want more parenting news in your ears? Listen to the latest episode of This Glorious Mess in which Holly Wainwright and Andrew Daddo discuss the biggest trends of 2017.