Well, it's a really strange concept as Attack on Titan is a fictional entity and can't actually 'watch' a fanfic. But if we were to be creative, maybe it would be like the characters in the series are observing an alternate version of their own story. They might be shocked, amused or even inspired by the different plotlines and characterizations in the fanfic.
If Attack on Titan could watch Attack on Titan fanfic, it could lead to some really interesting scenarios. For example, the characters might react differently to how they are portrayed in the fanfic. Eren could be either enraged or intrigued by a version of himself that is much more docile or much more aggressive than he actually is. Mikasa might be confused or pleased with how she is depicted in the fan - created stories. And the overall world of Attack on Titan could seem both familiar and strange when seen through the lens of fanfiction.
This is such a wild idea! Since Attack on Titan is a work of fiction, the idea of it 'watching' fanfic is purely imaginative. However, if it were possible, the Titans themselves might not understand the human - written fanfics at all. But the human characters like Armin could potentially learn new strategies or ideas from the fan - created stories. It could also cause some chaos as the fanfic might have different lore or interpretations of the world, which could either enhance or disrupt the 'canon' understanding of the Attack on Titan universe.
Chapter 11, "She Smiled, He Panicked", is the clearest early answer because it turns Don's situation into a concrete plot event. A useful checkpoint is the way the scene starts with After a meeting, Shang Shaojing pinched the bridge of his nose,...
Chapter 408, "You Can't Be on the Same Team!", is the clearest early answer because it turns Yu Li's situation into a concrete plot event. The chapter turns that into something concrete by moving from Zheng Xun fell silent after he understood the situation. to He suddenly felt a sense of crisis..
Chapter 169, "This is What Happens to Show-offs!", is the clearest early answer because it turns Jiang Li's situation into a concrete plot event. The chapter turns that into something concrete by moving from Everyone: "What?!" Seeing the shocked and bewildered expressions on...
Chapter 303, "Child Disobedient? Pull Down Their Pants and Spank Them Hard!", is the clearest early answer because it turns Pants's situation into a concrete plot event.
Chapter 5, "Beast Taming Codex", is the clearest early answer because it turns Toothed Dogs's situation into a concrete plot event. A useful checkpoint is the way the scene starts with Mother's voice was a few decibels louder than usual, yet her facial... and follows through with The glow of the Star Array covered the Fire-Toothed Dog's head, and....
Chapter 22, "Number 7203", is the clearest early answer because it turns Xiang Hao's situation into a concrete plot event. The chapter gives readers a real answer by opening on Hearing this, Su Yinwan looked at Shang Shaojing with a face full of...
Chapter 198, "Jiang·Deceitful·Li is Verified", is the clearest early answer because it turns Jiang Yan's situation into a concrete plot event. A useful checkpoint is the way the scene starts with He wrapped his arms around himself and stepped back half a step,...
Chapter 346, "This person doesn't seem to like her very much", is the clearest early answer because it turns Hua Country's situation into a concrete plot event. The chapter turns that into something concrete by moving from Yes," Jiang Li said, "I learned that this 'Night Walk' is an...
Chapter 281, "Zhao Lang, Are You Willing to Take a Gamble?", is the clearest early answer because it turns Jiang Yan's situation into a concrete plot event. Early on, In his dream, he found himself in a strange world..
Chapter 195, "Woke Up and the Base Was Stolen?!", is the clearest early answer because it turns Su Yinwan's situation into a concrete plot event.