The ? emoji is commonly referred to as the "new moon face" emoji. In simple terms, it represents a new moon, which is the phase of the moon when the sun and moon are aligned in the sky, and the moon is not visible from Earth.
However, on social media and messaging platforms, people often use this emoji in a playful or humorous way to add a touch of mystery or mischievousness to their messages. It can also be used to convey a sense of darkness, secrecy, or a hint of something hidden or concealed. Some people use it to indicate that they are sharing something they find amusing or intriguing.
Emojis can have different meanings and interpretations based on the context and the individual's usage, so it's essential to consider the overall message and conversation when trying to understand why someone uses a particular emoji frequently.