Your question is QA Day and SDLC With Vague Requirements. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
Describe how a typical day of a QA would go, and explain how you would handle QA projects with no requirements or vague requirements, including your understanding of SDLC.