TikTok, the video sharing app with 500 million monthly users worldwide, is much loved by a new generation of outspoken, socially-active smartphone users. The rules, behaviour and morals of the platform are worlds apart from other social networks – the videos are mostly 15 seconds long and tall, not square. You scroll up and down through videos; you don’t swipe. Tik Tok positions its culture for go-getters, activists and dreamers who value action and engagement over likes and followers.

To learn more about what makes Tik Tok tick, the platform’s US marketing director Stefan Heinrich brought video creators Anna O’Brien and Andrea Okeke on to the stage at the Cannes Lions for a session entitled “#no filter – the activists disrupting entertainment”.

Heinrich told the session that today’s youth are more critical of advertising than ever – people under 28 years old are half as likely to engage with branded content than those who are older, he said. “We need to adapt to their style and speak their language if we want to keep up. Real life is winning,” he said.

Heinrich asked the creators whether today’s youth really do suffer from a declining attention span, as many have said.

Okeke responded that content has changed and today’s children and youth – so-called Generation Z – are turning away from long-form content. “With 15 second videos, they can watch them and re-watch them, but they see everything. They notice the smallest little error, they are like detectives.”

O’Brien added that for older generations, the details of a piece of content are less important than the overarching story. “But in today’s generation, attention to detail is rife. A lot of creators are doing multi-layered content so you have the real story at the front but then you have all these little vignettes in the background that are secondary experiences where people watch them again and again. It could be someone taking selfies in the background. These become part of story lines on top of each other.”

She praised TikTok as a platform where that creators really can be themselves. “As a creator on other channels you get put into a box, you are a beauty person or a fashion person or a lifestyle person, there are rigid little containers they put you into whereas on Tik Tok, one day I’m doing a dance video, next day I’m running around doing something silly, or hitting someone with a milk jug.

“There’s all kinds of different components to who we are and that allows us to be authentic and that is a really important part of this generation’s identity. We are not seeking to identify people with one word.”

This makes Tik Tok a tough terrain for marketers to negotiate as they work with creators to promote their brands through videos. Some brands make the mistake of trying to repeat the approach they have used with TV commercials or other social platforms. They need to understand the peculiarities of TikTok and work with creators as individuals.

Okeke, who has created TikTok content to promote brands such as Netflix and Chipotle, said: “I will only collaborate with a brand that I believe in, I am not going to collaborate with a brand I don’t use. I make sure I can advertise it authentically.” She advised marketers: “Try to allow the creator be creative and to do what they love.”

O’Brien said the world is full of brands which are trying to be neutral and comfortable. But that approach doesn’t work on TikTok, where people are trying to make strong statements and have a defined point of view. Comfortable, safe content is just boring.

O’Brien added that she feels she is on an important mission with TikTok. “I spent my whole life being told what I couldn’t do, so I decided to do it anyway. Now I tell people that the boundaries the world tries to place on you don’t need to be there. Just do what you love and screw what others tell you.”