The elevator trim stall demonstration shows what can happen if you apply full power for a go-around without maintaining positive control of the airplane. They’re a demonstration-only maneuver; only flight instructor applicants may be required to perform it on a practical test (FAA Airplane Flying Handbook).
FAA: Pilot’s Handbook of Aeronautical Knowledge (2023)
Version 2023: https://www.faa.gov/regulations_policies/handbooks_manuals/aviation/faa-h-8083-25c.pdf…