Participatory culture suggests that audience members don't act as consumers, but rather prosumers, whereby the audience are contributors to a text whether it be through discussing it on social media, creating fan made content relating to that media product, or even by collaborating with the media product itself. This theory is especially relevant to Zoella, who is seen as an icon and has millions of followers online.
A quick search of 'Zoella fan art' produces multiple different artworks created by fans of the internet sensation, reflecting fans status as prosumers because it shows how they have taken the preferred reading of the text and want to further interact with it by dedicating time to drawing Zoella.
Another way in which fans are prosumers is due to the fact that they have prompted/forced Zoella to make certain videos in the past if they have had any issues with her or her actions. For example, in 2017 Zoella released an advent calendar with Boots that cost £50. Many fans complained that this was too high a cost and was exploiting their love of Zoella, with many parents also suggesting the price was too high for them to afford, as a lot of Zoella's target audience are not of an age where they can work. In response to this, Zoella released a video apologising for Boot's pricing but said that she had no input on the pricing, only the design. To may, this apology did not seem sincere, but Zoella has never commented on the product since.
furthermore, the way in which fans interact with Zoella could show how they are prosumers as it allows them to have their voice heard; Zoella often captions or ends her videos with a question for the audience, most commonly asking them for help, advice or to share their experiences relating to the subject matter of the video. This shows how Zoella's YouTube is not fully authorised by her but also by her fans due to the fact that, following the positive response she has received from fans, she has began to ask what they want to see more of on their channel and has based her content around what she knows the audience wants.