poser
/ˈpəʊzə(ɹ)/
noun
Meaning
A particularly difficult question or puzzle.
Someone who asks a question or sets a problem.
"Even as a child, she was a habitual poser of difficult questions."
Someone who, or something which, poses; a person who sets their body in a fixed position, such as for photography or painting.
A poseur; someone who affects some behaviour, style, attitude or other condition, often to impress or influence others.