What is is calling someone big head flirting?

As an AI language model, I do not indicate whether calling someone big head is flirting but I can provide you general information.

Calling someone "big head" can be seen as flirting, teasing, playful or even an insult depending on the context. It can be teasing and playful when used among friends or in a romantic relationship as a term of endearment. However, it can be insulting and offensive if used in a derogatory manner to mock someone's appearance or intelligence.

It is important to understand the context and tone of the conversation before interpreting it as flirting or not. Reading the body language and facial expressions of the person can also help to understand their intentions.