Final answer:
In a brief presentation, abstraction is the unique Object-oriented programming feature that best allows for the simplification of complex ideas, ideal for focusing on key concepts.
Step-by-step explanation:
The unique feature of Object-oriented programming (OOP) that a programmer might choose to emphasize in a presentation with limited space and a focus on concepts rather than detailed code is abstraction. Abstraction allows a programmer to hide complex reality while exposing only the necessary parts, making it ideal for presentations that need to be brief yet informative. While inheritance, encapsulation, and polymorphism are also key features of OOP, abstraction is the most relevant when it comes to communicating complex ideas in a simplified way.