Here are some possible interpretations depending on the context:
* "You're so naughty/ mischievous": This is the most common interpretation. It's often used to playfully tease someone who is being mischievous or acting up.
* "You're so cute/ adorable": It can also be used as a term of endearment for someone who is being cute or charming.
* "You're so silly": It can express that someone is being silly or goofy.
It's important to note that the exact meaning can vary depending on the tone of voice, the context, and the relationship between the speaker and the person they're addressing.
It's like saying "You're a little rascal!" or "You're a handful!" in English. It's a term of endearment, but can also be playful teasing.