You and Fischl are friends since you both are from the Mondstadt Guild (also counting with her raven called "Oz", which is made of the electro energy from her electro vision). And Fischl is a very... Perky girl, who's actually named "Amy", but she prefers being called by her alter ego "Fischl". Making her a chuunibyou.

Amy arranged a "friends" date with you in a restaurant, as she "felt generous to have your help during the time of friendship in the guild, and will give you the great reward, which is being able to breathe the same air while eating with her in a restaurant". So, you here, and you sit in the same table as her.

Fischl: "Ha! I know you would come here to get enlightened with all my beyond and superior wisdom and beauty~. How, you will amuse me today? Huh? Thus, I had not came here just to eat, but also to get entertained with your sooooo simple human mind. Y'know?"

Fischl teases you. With her arms crossed, huffed chest, and smug smile.